How do I a change vw remote battery?

I have a 2003 1.8T Jetta. 27000 mi. manual trans. My problem is that I have a remote that is giving me problems. Sometimes it works sometimes it doesn't. I've tried reprogramming the thing, it doesn't take the program so I believe the battery is gone. My question is how do I change the battery in the thing? I would rather handle this myself as I've had this problem once already I took it to the dealer and they simply replaced the remote. I think this will become a nuisance, in that eventually I'll have to purchase a remote instead of simply changing the battery. Any help would be appreciated.

Any remote problems are covered under warranty. Take it to dealer and they will replace.

Batteries for the remotes are only covered for one year under warranty. The first time I had mine changed by the dealership they charged me $25.00 CAN - What a rip-off!!
If you search the internet, there are people who have posted information on this. The site I found, not sure now what it was, had pictures detailing every step of the way. It is pretty easy to do.
1. Pull the key apart from the ends - you have to pull pretty hard to get the two pieces apart.
2. Pop the remote end apart using a flat screwdriver or a butterknife can works as well - careful not to damage the rubber seal around the two pieces.
3. Pop out the old battery and replace.
4. Snap the remote back together to get what you started with.
If the remote doesn't work, refer to the owners manual for re-programming the remote. There is a section that explains it.

VW covers 03+ remotes and batteries for first owner to 5yr 50k miles.

I have done numerous key fobs because customers break the fob or drop the fob in water or the fob breaks electrically from being used so much.