If Steps 1-5 don't work, try to cut off the flange or grind it with an angle grinder. Ideas on Lowering a PVC Toilet Flange. 1. Use a PVC pipe cable saw and cut off the top of the flange. 2. Wedge the pieces out by cutting some segments using a mini hacksaw. 3. Remove the flange rings. 4. Cut down the pipe until it is flush with the floor. 5.