I have a clarion HU that I am trying to remove, do I need special clarion removal tools to do this? I can't figure out how to release it to pull it out. Thanks.

If it mounted using the ISO mount brackets then all you need to do is disassemble the dash and remove the screws from the side of the unit. If it's mounted in the sleeve, then you need the keys that came with the deck to release the unit from the cage.

slid right out after that.
Thanks.