I had the same trouble with mine but taking the tank off won't really help taking the airbox off will though. i got mine off with a freinds help slipped a very small screwdriver under the locking tab (very carefully) and got a small hook under the front edge so that he could pull straight out while i held the locking tab open. later when i had to get them off again i tooke the airbox out of the bike and just grabbed them. but they are very hard the first time.
if you get a good map for that please let me know i have a devil slipon and TRE and really don't have the money for a custom map. good luck.