GOD BLESS YAHOO ANSWERS
Strip off any "flakes" of chrome that are readily visible. Depending on the material underneath (steel or aluminum), use either a steel or brass wire wheel to get the majority off and smooth. Be agressive here since you want to make sure anything not firmly adhered will come right off. Smooth the edges of the "good" chrome and the substrate with a fine wire wheel (finer than for rough removal).
An important part; "scuff" any remaining "shiny" chrome with a scotchbrite pad, 120-grit wet/dry sandpapaer or a wire wheel with fibers that can truly scuff the "shine" out of the chrome. It is painful, but you have to do it to give the powder coat something to adhere on a molecular level when it cures.
Give the wheel a muratic acid bath to remove any oils or contaminates. This stuff is really nasty and dangerous (used to unplug toilets). You can probably get away with Aircraft Stripper which is used to remove paint (I know, no paint on chrome right?) but it will remove all oils, etc. Rinse the wheel VERY well. Rinse again, rinse again.
Now for the fun stuff; put the wheel in the oven for 1 hour at 400 degrees, remove and allow to cool. Using gloved hands (cloth preferred) (so you don't contaminate the part) it can now be powder coated. Do not allow it to sit around for days after this step or dust will settle on it, ruining any future powder coating until the wheel is cleaned again.
At this point, you can powder coat or bring it to an knowledgeable powder coater; not an industrial powder coating shop. Bring it to someone that specializes in high-end automotive and/or motorcycle work since that requires much more attention to detail that coating a lamp post or stop sign.
Finally; since your wheels are already flaking chrome, chances are you may be better off putting them on eBay for someone else to worry about since a truly professional powder coating shop will charge between $100 and $200 a wheel for cleaning up the wheels, smoothing the chrome, dealing with nasty chemicals, rinsing and re-rinsing and finally applying the powder (price goes WAY up with translucents, prismatics, etc). If you decide to do the wheels you have then you can expect a 12+ year lifespan before any noticable "dulling". The powder coat itself, if done by a professional shop, should come with a 5 year warranty (curb-scrapes excepted).
It may not be the answer you looking for but too much information is better than not enough.
im sure you could probably get a local shop to bake them for you if thats the route you want to go, not sure how much it would cost to get them rechromed probably some of the samestuff would have to be done like takeing the old chrome off and cleaning