Here's a clean solution (no glue involved) on reattaching the bumper. Use some heated needles and insert them (from behind the bumper) exacly where the original attaching stubs were. Insert them into the holes on the car's body (you might want to wrap them in a little bit of scotch tape, so they'd firmly stay in place). Do not use thicker pins or nails, as, when heated, they might bulge the plastic bumper and ruin it. Once the bumper inserted into the holes and the needles cut to a shorter size, you can bend them from the inside of the car front.
Hope this was helpful.
:cheers
Hope this was helpful.
:cheers