Need help switching my apartment cable from directv to comcast!

[kmhs1618]

So, I know that right now it's hooked up to directv. I found the cable box for my whole building on the side of the building, and it's unlocked. There's a lot of cables and splitters with labels of apartment numbers. All of which connect to two different end box things. Right now my comcast isn't working because all of my cable outlets are hooked up to directv. Is there anyway I can change it myself? I can post pictures if needed!

 

[Juan]

Did u call comcast?