Well...unless you're adept at working in VERY tight quarters....I'd seriously suggest sending it back to Innoken...the o-ring is NOT likely to be easily replaceable locally...and attempting to open the case will likely VOID any warranty!

If you really want to TRY a repair....I will tell you.....the screw heads are a T6 Torx...
From here.....you're on your own, unless someone else chimes in with a better plan....
