how difficult is it to remove the stock head unit?
 

i have the symphony and am thinking about putting the IceLink in. all i need is the factory keys to remove it?

Easy when using the factory removal tools
 

Put two in on one side, pull out slowly (had to apply pressure on the keys sideways - can't remember if it was outward or inward to prevent the keys from popping out) and once it gives a bit, do the same on the other side. It should then slide out easily.

Re: Easy when using the factory removal tools
 

An even easier way to remove the radio is to buy 2 sets of keys. They're only $6 on eBay. Then all you have to do is insert all 4 keys and the radio slides out.

Are the keys the same as in previous models?

Yes