How to remove the bolt catch on the M4?

[MILITATED]

Last noob question.

So I nearly have my gearbox out, and the only thinking blocking it is the bolt release. How do I take out the bolt release? I've watched a few disassembly videos but they don't take it out. One guy did, but he didn't exactly show how to do it. Anyone know?

 

[MILITATED]

Ah, I found out that there is a little pin. The glory of low lighting...