You can rig up your own out of a coat hanger or I have heard of nails working. But if you have a autozone or a place like that, they should have the tool for like 4 bucks. I would reccomend getting the tool.
just be careful when using any tol to remove those radios. make sure they click in where they are supossed to. i've seen many times where peoplepush them in too far and bend the locks where they cant be used to release the radio and now have to find another way to get it out
$2.99 at walmart. Way worth the $3 dollars to not have to worry about messing it up in anyway. And be super super super careful to make sure they click and that you don't have to force anything. It will slide nice and easy when you have it hooked up right.