removing a %$#*&(@ing alarm?

truck won't start - alarm won't shut off - have two hand/keychain "off" thingies, neither of them are working. Is there a small battery in the alarm itself (not the vehicle battery)?

Anybody know how to take these stupid things out? I hate it anyway. All they do is go off when they shouldn't. I would never buy one on purpose, this came on the truck - I thought it was aftermarket, installed by the previous owner, but husband is saying he thinks it came with the truck.