Key Fob

I have a 99 Yukon, bought used. I received two key fobs which both work. But I do not see a way to replace the battery inside, that's assuming there is a battery inside. There are no screws and no way to access the interior workings of this fob. I've had problems with it sometimes not locking/unlocking but that seems to be random and could be positional. Around hospitals it just doesn't work. Is there a way to change the battery? Had anyone else seen the random locking not work?

Any thoughts?

TIA

Were the keychain hooks on..you see a groove.
put a coin in there and twist. the cover will open the battery lies inside.
Hope this helps.

You know I was so focused on looking for a screw (OK, stop laughing) that I didn't see the groove. Thanks for your response..