I'll check tonight, but my recollection is that I did not totally disassemble the truck.
I first carefully bent one sideframe out with a flat bladed screwdriver, at the end of the truck which had the bad wiper connection, just enough to be able to pop the axle and wheels out of the sideframes.
I believe the truck is connected to the caboose frame by one screw, which I unscrewed to get a little more wiggle room with which to be able to access the wiper. I kept the wires still attached to the truck, but I was now able to maneuver the truck a bit better to access the offending wiper arm. I used a pair of locking tweezers and my fingers to grab the wiper arm and bend it back up just enough so that it would clear but still contact the axle when re-installed.
I then screwed the truck back onto the caboose frame. Then put one end of the axle back into one sideframe and bent the opposite sideframe open a little until the axle point slid into that sideframe's slot/hole.
I then pushed the wiper arm down onto the axle with my fingers just to insure it was making good contact. Sprayed with contact cleaner and oiled the axle ends.
You need to be extra careful when bending the sideframe out - just enough and only as long as it takes to quickly remove/re-install the axle - so as not to break the sideframe. Not necessarily for the faint of heart.
Hope this helps.
