You need the special removal keys/tools to get it out the easy way. There are two slots, one on either side of the radio, where you insert the keys, then the radio just slides right out.
I'm not sure where you can get them. I've had my set for many years, being I'm an installer. You might be able to go to a stereo shop and have them pull it out, they shouldn't charge you much if anything, its only a 10 second job.