Is there a special way to remove the removal keys once you have re-installed the Symphony II unit? They don't release easily from the radio and if I just pull them out they feel like they might be damaging either the key of the radio lock.

The unit should slide back in on its own.

take the keys out before you re-insert the headunit. If they have trouble coming out press the side expanding tabs in on the side first then try and release the keys. Then slide the radio back into place.