Install Sonic Robo Blast 2
Download and install SLADE
Create a new folder for your mod files
Learn the SRB2 file structure
Make a WAD or PK3 file
Add your custom sprites, maps, sounds, and textures
Create or edit Lua scripts if needed
Define objects, enemies, and gameplay changes in DECORATE or Lua
Test your mod in SRB2
Fix errors and adjust gameplay
Package the final WAD or PK3
Load the mod with SRB2 using the command line or launcher
Share the mod if desired