I never replaced the wires on these coils but I have on other bikes. I don't think the wire needs to be anything but cut flush as it is only a one wire operation. There should be a pin sticking out of the coil that the wire goes on to and when you screw the cap back down it tightens it again that pin.
Other on this forum may know more but as far I know, you can go with a flush cut. Pay attention to how the old wires are when you pull them out.
Grace and Peace to you!