Okay, My clan wants some fixes to Battery and Fueldump, but I need to decompile these maps, and after half a year of mapping I still don’t know it.
So here’s my question:
How do I decompile .bsp files?
Decompiling
Kic
(Kic)
#2
Do a forum search. I readed this topics. Decompile and change these original maps is against rules , you should know
Flippy
(Flippy)
#3
If you don’t have permission from the mapper (in this case the company) it’s not allowed to change the maps…
Also, if you decompile a map it will lose vital information, for example, all brushes will be structural. All texture alignments will be f*cked up… it’s probably more work to change an existing, decompiled, map than to make your own map…
If you really have to do it though, you could try to contact the mapper for the original .map file… although chances are small in the case of battery or fueldump 
kamikazee
(kamikazee)
#4
As an alternative, you might tell what changes you need. ETPro allows you to modify a lot of things trough map scripting and can be used to alter maps without decompiling.