There isn't much to removing those tiny Resistors, just cover the whole thing in solder and 'wipe' it off the board with the tip of the iron, bout as neat and clean as ya can do it without having a Hot Air Rework setup.
You'll know the trace is cut when you can see the board under the trace, use a good magnifying glass during the whole procedure. That's why you make the cut in a V, what you're doing is going into the board thru the trace from 2 angles. The top of the V are the 2 cuts that are 0.5mm apart or so, and the tip of the V will be into the actual board, so you're taking a tiny 'chunk' out of the board there and the trace comes with it. The actual trace is thinner than paper, so the V cut doesn't have to be very deep at all.
It's still far easier and cleaner to remove the Resistors by just covering them in solder and using the tip to wipe them away, but use what ever method you're more comfortable with and I recommend ya practice both on some other board with SMT parts and small traces that are close together so ya get the actual 'feel' of doing both before laying the iron or blade to your RF board.