That's what I was thinking too..some bumpercovers are structurally different and if you just cut out the sections it wouldn't work out that well.
OTOH, maybe yours isn't like that and *would* be OK to cut

Maybe a rotary tool like a Dremel. I'd use a flex shaft and I'd tape the area of operation, marking the cutline on the tape.
Heh heh, is is one of those "hope the hand of God is on your shoulder" things IMO, I'd sure hate to botch it up.