I need to replace the release handle on mine ( 97 SL320 ) as well but, have not looked at it too hard.

EDIT, remove wrong info
I think there is just a single screw accessible from under the handle without removing any trim. EDIT remove wrong info

ADDED
Looked at my SL today, the handle is pressed on / molded to a metal tab and does not have a screw. Next time I'm at the dealer I'll see if the handle is sold separately.

I did see how the carpeted lower dash / knee bolster comes off. Feel around the top where the carpet meets the plastic dash, there will be screw holes hidden in the carpet nap. There look to be 2 on each side of the column. Not sure what holds the bottom of the carpeted lower dash / knee bolster , but it should be apparent with a closer look. ADDED


It looks like the same part as the 97 E320 parts car I have.

Now if the cable is broken the under dash / knee bolster would have to be removed, have not looked at taking this apart at all.