I was able to remove 3 of the 4 front bumpers bolts. It looks like there are no rubber bumpers installed. This last bolt loosened about a 1/4 inch and then just turns in place. I pull on the bumper while I ratchet but no extraction.
I can't get a cut tool in there to cut the bolt. Here's a picture through the horn grill opening. Help!

Click to view attachment

I would try to get in there with a cut off disc in a grinder, (from the inside of the wheel well), and cut the bolt head off. Yes, the PO forgot the rubber spacer. Once the bumper is off, a new nut can be welded in place, on the bumper.

It you can get a thin pease of sheet metal.maybe hack saw blade put in bolt threads between bumper and back it out

Did the weld but in the bumper come loose? If so try to get a pair of vice grips on it while you turn.

Plan B: drill the head off the bolt from inside the wheel well.

Wedge something into the gap between the body and the bumper,it will cross thread its way out .
When you reassemble glue the rubber dog bones on to the bumper with contact adhesive,makes things a lot easier.

Don't use solvent based contact cement. It contains chemicals that will degrade the rubber spacers. I just use masking tape.

Sawzall will get it.

Sawzall

Access is the main issue...can't take the valance off since bumper is on. Have to take a look again tonight.

Be great if there was some acidic putty or gum you can just put on the bolt head and dissolve it....you know like how rust dissolves the rest of the car...

Suck, but yes you can remove the valance in your situation.
You have one bolt holding you up....

Many of us have had to deal with this..

Either a cut off wheel or a saws all will be what you need to use.
The valance may require you reach into the front trunk and cut off the ends of the bolts.

If it's the front bumper, both bolt heads can be cut off with a dremel or cut off wheel.
If it's the rear bumper, the two bolts in the trunk can be cut off easily, and the lower ones, while harder, can also be cut off with a cut off wheel.

From the picture you posted, it looks like a sawzall with a long metal blade will reach it and cut the bolt.

These are time that harbor freight is part of your new route him from work.

It looks like you have a gap in there.

Push the bumper IN hard.
That should expose enough of the bolt head in the fender-well to cut it off?

All great ideas. Have to look tonight and see what I can do with what I have...ya maybe a trip to HB....I have that 20% coupon somewhere.