Your deck should've come with removal tools. They're 2 metal strips that u slide in on both sides of the Headunit and they lock in place til you slide it out. For some reason my Sony HU didnt come with them, which I realized when I tried to replace it a while back. Go to your local shop or even a best buy installation bay may let you use theirs, or you could buy a pair. They're cheap little things, should only cost a couple of bucks.

edit: I had almost that same deck, and upgraded to kenwood also, definatley an upgrade you'll be happy with