How to put battery in key?

[Doug Rudoff <drudoff@homer.spry.com>]

OK, I know this shouldn't be that hard and I feel somewhat stupid for
asking, but I need to put a new battery in my "keyless entry key" for the
'92 100 CSQ I bought this week. I've tried what I thought was the obvious,
that is to press down the tab by the hole in the key, but without luck and
I don't want to damage the key by prying apart the wrong piece. 

I don't have an owner's manual, so any help would be appreciated.

TIA

Doug Rudoff                                                drudoff@spry.com