If it isn't terrible U can venture over to Harbor Freight and get a heat gun for about $10 and apply some heat to the cover (keep it about 5-6 inches from the paint) and try to push the dent out from the back side, use a handle from a screwdriver and gently massage the plastic. Do not use the screwdriver end, just saying.

Repair IMPOSSIBLE replace 700 - 100 depending on where you are. Scrap yard will be much cheaper if you can find a replacement at one.

ABS plastic (what the bumber is made of ) will not reform AND hold it's strength/ do it's job. So it is a REPLACEMENT not a repair that you need.

About $700.

About 700.01

I have a 2008 Nissan quest and some one backed up in to me at a parking lot and left a dent in my front bumper. Now it looks like my bumper is made from plastic, so I would like to know how much would it cost to undent it (the insurance is would charge me a $1000 deductible )