So picked up an LS460 that had the horrible gummy trunk button issue. Instead of buying a switch and cover I chose to spend only $6 and get just a cover off of ebay and thought I'd just point out a couple of tips and tricks while doing this swap. The trunk buttno fix has been pretty well documented so I'm not going through the process to show you how to remove and install etc just google it and you shall find what you seek.
With the trunk trim removed go ahead and clean the area behind the trim. Mine wasn't too bad and chances are neither will yours but the edges etc are hard to get to and this lets you clean it unobstructed.
The same goes for the back of the trim itself. I cleaned it and because it is plastic I went ahead and just gave it a quick spray down with 303 aerospace or any sort of conditioner on the whole trim and the clips.
My key access hole was pretty disgusting so I cleaned that and thought it was an appropriate time to spray some silicone grease into the key hole itself.
As you can see my switch cover was pretty melted and it kinda filled in all the cracks and crevices of the switch itself making the switch inoperable. The only way to open the trunk was through the switch inside the car or the keyfob.
Dismantling the switch is not rocket science it comes apart as in the picture above, again do so at your own risk but it is pretty straight forward. scrape all the rubber off the parts etc. Tip: once you scrape most of the rubber off you can use brake cleaner on a rag to wipe up any residue etc.
Once all the goo is off putting it back together is reverse of disassembly and viola you have a working switch. I think the switch is like $80 which is really not a bad price. But if you don't have an hour to kill I'd just get a complete switch and swap it out. Good luck...
- AJ Abraham