For contributing, you will need the ARMIPS exe to compile your code changes for testing. Grab it here and select the latest automated build: https://github.com/Kingcom/armips 

1. Run Compile-log.bat (this also outputs a log file for useful debugging)
2. Copy the bytes from "Randomizer.bin".
3. From your already modified DECOMPRESSED ROM (rando.xdelta patch already applied), paste the bytes in "Randomizer.bin" to your ROM at 0x00EFB0B0. Make sure you aren't adding bytes, but overwritting existing bytes at that location.
4. Save and test your edits.