Use RPKToRSD2.exe to decode .rpk files into human-readable .RDB2 files
Make edits using any text editor (Windows Notepad works, but Notepad++ is much more convenient)

Afterwards, use RSD2ToRPK.exe to compile!

You can place RDB2Auto.exe alongside RSD2ToRPK.exe into the main folder;
Then, leave RDB2Auto running as you make edits - it will automatically run RSD2ToRPK whenever you save a .RDB2 file,
saving you the recompilation step!



Credit goes to amilmand for creating these tools!
Improvements by g13ba, RDB2Auto by EvilMcSheep