Exchange is only possible between games of the same generation:
Generation I.
Red, Blue, Green, Yellow
Generation II.
Gold, Silver, Crystal
Generation III.
Ruby, Sapphire, Emerald, FireRed, LeafGreen
Generation IV.
Diamond, Pearl, Platinum, HeartGold, SoulSilver
Generation V.
Black, White, Black 2, White 2
Generation VI.
X, Y, Omega Ruby, Alpha Sapphire Machok will be able to evolve into Machampa after exchanging it with another player. In other words, you need to find another player with the same console and generation of the game so that you can trade with them. When you exchange Machok, and he evolves into Machampa, ask the second player to return him to you. If you are playing on an emulator, then in order to improve Machok, you will have to find a workaround.
Steps
Method 1 of 2: Trading in the game

Step 1. Find a friend to trade or get a second console and game
To upgrade Machoka, you need to give it to someone. To trade, your friend must have the same console and generation of the game. In the fourth generation of games, Pokémon exchange is available via the Internet. The main thing is to be sure that your Machampa will be returned to you!
If you are playing on an emulator, it will be difficult for you to trade Pokémon. If you are playing a fourth generation game, you can modify the ROM file and evolve Machoka through leveling up

Step 2. Make sure you meet all the requirements
You will not be able to trade until you have completed all the requirements early in the game. For most players this will not be a big problem, but if you want to trade at the very beginning of the game, you will have to do the following:
- Generation I: You will be able to trade Pokémon after you receive a Pokedex from Professor Oak.
- Generation II: You can trade Pokémon after giving Professor Elm the Egg Riddle.
- Generation III: You will be able to trade Pokémon after you receive a Pokédex from Professor Birch.
- Generation IV: You will be able to trade Pokémon after you receive a Pokédex from Professor Rowan.
- Generation V: You will be able to trade Pokémon after you receive the Trio and C-Gear badge.
- Generation VI: You will be able to trade Pokémon after you have acquired two Pokémon.

Step 3. Put Machok in your group (generation I – IV)
In order for Machoka to be exchangeable in the first generations of games, he must be placed in his active group. In the latest generations of games, you can trade any Pokémon you catch.

Step 4. Connect two consoles
The connection method depends on the console model.
- Game Boy, Game Boy Color, Game Boy Advance: Connect two consoles using a Game Link cable. You won't be able to connect two different Game Boy versions. Enter the Unity Room on the second floor of the Pokémon Center to find another player.
- Nintendo DS: You can wirelessly connect to a second console if it is nearby. Fifth generation games have an infrared transfer function built into the cartridge. Here's how to connect two DS consoles.
- Nintendo 3DS: Press the L and R buttons and select the Player Select option. This will allow you to find people nearby or connect to the Internet and exchange online. When swapping Pokémon online, be sure to tell your swap partner to return your upgraded Machamp.

Step 5. Exchange your Machok
Machok evolves into Machampa immediately upon completion of the exchange. Then tell your exchange partner to return your Machampa to you.
Make sure Machok is not holding the Everstone, or it will not evolve
Method 2 of 2: Evolution Process When Playing on an Emulator

Step 1. Understand the process
You will have to use a special program that will modify your ROM file. These changes will allow you to evolve Machoka into Machampa, bypassing the exchange. Instead, he will try to evolve when he reaches level 37. You will need a computer to work, but if you are used to playing anywhere, you can transfer the modified file to your phone.

Step 2. Download the Universal Pokemon Game Randomizer program
With its help, you can change the ROM file and make it so that Machok (and other Pokémon whose evolution depends on exchange) can evolve in the usual way through leveling up. You can download this fan program completely free of charge at pokehacks.dabomstew.com/randomizer/downloads.php.

Step 3. Extract the folder that contains the program
Right-click the ZIP archive and select Extract All. Follow the instructions and create a new folder for the program.

Step 4. Launch Universal Pokemon Game Randomizer
Double click on the randomizer.jar file to run the program. This will open a program window with a number of different options.
For the program to work, Java must be installed on your computer. For instructions on installing Java on your computer, see How to Install Java

Step 5. Click on the "Open ROM" button and locate the ROM file
If the ROM file is in an archive, it will need to be extracted before you can modify it by Randomizer. You can use this program to work with ROM-files of any generation (except the sixth).

Step 6. Check the box next to the "Change Impossible Evolution" option
It's under the General Options section. This is the only option that needs to be checked in the program.

Step 7. Click on the “Randomize (Save)” button
This will change the evolutionary process for all Pokémon in the game that needed to be exchanged. Never mind that the button says "Generate". If you haven't changed the other options, nothing else will change in the game.

Step 8. Load the new ROM file into the emulator
Universal Pokemon Game Randomizer will generate a new ROM file that you can download to the emulator. If all files remain in their original locations, you can load your old saves.

Step 9. Upgrade Machok to level 37 and above to evolve him
The new ROM file will be modified so that Machok can evolve at level 37 and above. Like most Pokémon, this will happen immediately after leveling up.