Success!!!
in the end I pryed the drums off the backing plate enough to insert one of my gear pullers and easily pulled the drums.
I thought I'd share a tip :
on the drums there are 2 smaller holes parallel to each other about the center of the drum. Tap these holes with a standard tap. future removal can be achieved by placing bolts in both holes and using a air wrench to turn the bolts in. this method will push the drum off.
cheers
