the brake pads on my 1989 300E were recently replaced and ever since then the brakes seem bumpy and grindy at slow speeds. also the abs light comes on for no apparent reason. how hard is it to repair the abs system and could someone give me a step by step procedure for doing this? do the pads also need to be replaced (probably only about 1,000 miles on them)?
all help, hand holding and words of encouragement would be appreciated.

I think your abs wheel sensors are shot or they were damaged during the install. I would first take it back to the store that did the brakes.
I know the sensors can be cleaned, when they get crudded up they engage the abs at slow speeds, like just before you come to a complete stop.

yal, thank you for your reply. how and with what does one clean the sensors.

In your local parts store they have electrical contact cleaner that comes in a spray bottle. Its a little bit like carb cleaner as it leaves no residue. I would use that.