You need a high speed cut-off saw or even a Dremel tool will work also.The method I use to remove inserts from carbons is to remove the nock and slide in a drill bit and whip the arrow towards the floor.This will nock out the insert,I like to wad up a blanket to catch the insert and bit.If the nock is glued in,screw in a field point and heat the point and pull out the insert.This all depends on what was used to glue the inserts in,sometimes both methods may not work.Then if possible just cut the shaft shorter to cut out the insert if the shafts are longer then you need.