Editing .bsp files

[cuber3]

I'm wondering if it's possible to edit a bsp file in hammer.
I downloaded a nice map, but I'd like to change the music which is playing.
I only have the *.bsp file, which I cannot load in hammer

Could anyone tell me how to edit it (it's just for personal use, I'm not planning to steal the map or claim I made it) ?

 

[Raeven0]

You can't edit brushwork or add or remove brush entites without decompiling and recompiling the map. However, for changing the properties of entities (such as music), you can easily open the BSP in a text editor, browse to the music declaration, and modify it. Entspy performs the same function in a UI.

 

[cuber3]

Awesome, will I also be able to make the music louder with Entspy ?
I'll give it a try, thanks a lot