I had the same problem. To cut the hinges, I used one of the heated Knives, the ones that hold Xacto blades. I used a chisel blade. It was slow work, but the robart plastic cut fairly good with this setup. You have to watch when the blade is about to break through that you don't slip and push it into the wood. Start working the hinge area first, it has the least mass and cuts fairly easy. Once the hinge line was seperated, I then shaved off the nubs flush to the wood. New hinges were added near the old ones.

Don