GGPK Editing - Boosting FPS

[WAFFLES101]

Ello puppets,

I was editing and changing a few things in the GGPK file trying to remove some special effects such as rain and smoke.
I've failed to remove rain, it's very hard to figure out where to find in the GGPK for me, however, I did get to edit some other effects.

Changed:
Rainbow Searing Bond and rainbow sky in Dom's arena (also, green Templars, nothing special). If anyone could help me remove the other special effects, add me via Steam or Skype and we can work together.
Wanting to do this to boost FPS mostly.

[supervirus3]

maybe begin to explain how to decompile GGPK files ?