
1. Open the .gba you want to edit with HexManiacAdvance
2. Click and drag the .hma file over HexManiacAdvance.
   You should see a preview describing what the script will do.
3. Release. The script will make edits to your rom.
4. If you're happy with the changes, save.

Note:
.hma files are just text files. You can open them and read them if you want.