How to remove Onstar unit to install gps??

[rogue status hoho]

Hey guys so I am trying to install my 3.5" Tomtom gps into the spot that currently has the Onstar GPS unit and two black square units beneath it. I need advice/help on how you remove the onstar unit part. I took off the entire dash bezel and then pulled out the 2 smaller black cubes by just pulling on them until the popped out, but I can't figure out how to remove the Onstar part. Please help me if you know! Thanks!

 

[Narco]

there should be a clip on each side of the blank

 

[rogue status hoho]

there should be a clip on each side of the blank

Perfect! Just got it pulled out!! Ready to install the gps as soon as it gets shipped! aaggh i can't wait// will have pics asap