Our door runs at a slight slant and is 25mm above the floor at one end and 15mm above the floor at the other. To accommodate the carpet we want, we need to shave a bit off the end of the door where it hangs closest to the floor, so that it is at least 20mm above the floor at all points. What is best way to do this, without taking the door off the hinges? Door is a 1 hour fireproof wooden door. *reason for not taking door off hinges is that it is a soundproofed room and we don’t want to disturb any of the door fittings etc.