Can anyone tell me "where" to find step by step instrcutions on replacing the dimmer switch on my 1999 Buick Regal? Any online sites that offer such detail?

Thanks

Do you have a factory service manual for the car? If not, it might be worth picking one up off of ebay (electronic copies are usually less than $15) and you'll find a full wiring diagram for the car.

Disconnect the negative battery cable.
Disable the SIR system.
Remove the inflatable restraint steering wheel module.
Remove the steering wheel & trim covers.
Remove the steering column wiring harness from the harness retainer.
Remove the two wiring harness straps from the harness.
Remove the steering column bulkhead connector from the wiring harness.
Disconnect the grey & black connectors from the multi-function switch steering column bulkhead connector.
Remove the retaining bolts from the multi-function switch.
Remove the multi-function switch.
Reinstall in reverse order.

Hope this helps.