My 850 had the bumper pushed back a little on one side. I guess they hit something obviously.
So the bumper now extends into the wheel well about an inch and sometimes it rubs on the tire.
How can I pull the bumper forward?

 

You should try to get yourself a used new bumper support.It is just a big aluminum bar that bolts to the bidy of the car.

 

is that easy to replace?

 

It is pretty time consuming.
If you look from underneath there is a bolt on each side that goes from the bottom of the car up.That loosens the bumper.Make sure all the rivets are out in the wheel well area then it will slide off.
Then you will have to play with the tabs to release the cover from the aluminum support.