I've done this and regretted it. If you tear the tape off, sometimes you'll wind up with ragged tape bits on the leading edge. Tape bits which contain deadly tape stickum that will wait until the film is mostly loaded and then stick to something inconvenient. Once I've cut the tape free, I make very small angled cuts on the leading edge, to help the film flow through the reel. This is important because the leading edge of a slice of TMAX is actually sharp enough to cut the teflon surface of a reel.
Old reels get scratchy and sticky.
Scissors or rounded toenail cutters work great. Do not cut the angles too deep because if you do, they will actually make it easier for the curling front edge of the film to slip out of the rails and produce a film-jam. That's a piece of backing, actually, cut the way I usually cut the end of a roll of film. Actually, I managed to load the backing onto the reel, in the process of developing this. Once I've got them both aligned up at the top, with the opening facing left, I grip the leading edge of the film in my fingertips and gently pull it into the reel.