Essentially I just pried it open using a flat tool. You could use a flathead screwdriver. Put it in the gap, then rotate it a bit and it will pop open just a bit. Continue moving around the fob and it'll open all the way up. Don't jam it in too far or you might damage the seal.When I bought my 2012 K1600GT in Jan I got two keys/fobs. One seemed dead and one seemed extremely sensitive. You could just lay your finger on it and it would flash rapidly. I took them both to BatteriesPlus and let them fit new batteries. The one that was dead now has life, but acts the same as the other one. Which with new battery acts the same. I followed the manual and paired them to the bike and they act as yours. You have to push the button several times to get them to actuate the locks. They rapidly flash very sensitive. The BatteriesPlus guy said they could open it up and look at it, but would take no responsibility if they broke it trying to get it open. It depended on if it was heat welded or just glued. After seeing your pictures, I may let them have a look at one of them. How are they sealed and how did you get the case split?