Need advice on what to do about this fitment issue, Revell ‘68 Mustang

The bumper fits perfectly onto the body except for this one little lip. If I bend it a little bit to make it flush, it just pops back. I’m scared if I try to bend it anymore that it’ll just break. Any ideas on how to make it stay flush until the glue dries? Only thing I can think of is a clamp, but I’m not even sure how I’d position it. Some help would be appreciated! Thanks.