I bought Trumpeter's E-50 kit so I could use its Schmalturm for my Dragon Panther II kit, whose Schmalturm is too big all around. I modified the Panther II hull and Trumpeter turret to allow it to fit on the hull, but it still sits too high due to this thick ring in the picture, indicated by my red arrow.

So how would I go about trimming that ring down so the turret will sit lower as it should? I have thin sanding files but they can't reach the innermost part of the ring; they get stopped by the ring above it. I also don't want to use my modelling knife to cut it down because the force required to cut into it is high. I run the risk of cutting a section off the ring and the knife flying into the actual base of the turret, damaging it. Any help would be appreciated.
