You mean the two adjusters either side of the backing plate are missing???
That's tough - and surprising if it's the case. Usually you can just back them off and the hub/drum comes off easily. If the drum is very worn there will be a lip which the shoes may be hiding behind.
Not sure whether fiddling with the anchor pins at the bottom is going to make much difference either. Is the drum moving at all? Once it is off a little you can get a large screwdriver in either side between the backing plate and drum to carefully lever it off. If the shoes are adjusted too far out you'll feel it spring back when you let the pressure off.
Last resort is of course the sledge hammer to demolish the drums.
