Jeff,

Short of taking the bumper's to a plating shop and having them strip the
chrome off
Here is a way to do the job------

Start with 180 grit on an electric or air obital sander first.
If that doesn't cut the surface of the chrome start with 80, until the
surface is uniformly dull.

Then lay a coat of acid etch zinc chromate primer on the bumper's to
seal the metal, scuff this with 180 after it dries, and then put a good
heavy coat of a filler primer     (Sherwin Williams Ultra Fill is the
best)
sand this with 320, and add more primer as needed to fill imperfections,
and paint. ( add a flex agent to the paint, or use Imron to ward off
rock chips )

Refinishing the bumper's using this system, will give you reasonably
long results.

Good Luck,

            ______________
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     ~~~ ~||-(())----(())-|

Terry--
74 Campmobile- (Clementine)
85 GL- (Delilah)
86 BMW 325 ES- (Eva)
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~     "In life, it is much better to want
something you cannot have---

Than to have something you can't get rid of"

(T.K.)