Spark plug removal


Tried to change my spark plugs today, but had a difficult time pulling the airbox off the carburetors after loosening the clamp screws.
I didn't want to force anything.  Do I have to? Or, what did I do wrong?
Mine required a little force but not much. Just enough to get all the rubber collars to start moving. Once you move them enough to get them going it comes right off. If you think getting the airbox off was tricky just wait until you try to put it back on and get all those rubber collars fully seated on all of the throttle bodies! ;)