Pat, sorry for the delay in answering, but was at the SE Rally in Savannah, eating wayyy too much food and having a great time? ;D .
I had rust on the top and bottom of the step, so I removed them completely off the coach (after making sure they were in the extended position). There are the 4 mounting bolts/nuts, and the electrical connections. Make sure to pull the fuses to the steps to make sure you don't short something out (there are several circuts to the steps), and double check everything electrical to make sure there are no live wires (12V) when disconnecting them. If you decided to try and tape things, just be aware that no matter how well you mask and cover, an errant wind current wil show up just as you push the button on the can, sending the coating is some oddball direction. You will be happy you took the time to take them off, trust me.
Wherever the coating was lifting, I used a pick to pop the "bubble" of coating and break it off to where the coating was still firmly attached to the steps. The rusty metal was scrubbed with a metal brush until all the rust was gone. I did use some sandpaper to feather the hard edge of good coating to the wire brushed area. I didn't see a need to remove any previous coating that was well attached. I used some coating I think I got from Autozone or Advance Auto. Wasn't that expensive (around $15, I think). It had a gritty texture that you were supposed to get by holding the can well away from the metal it was being applied to. I sprayed it close to the metal, and it made a great, fairly thin, gritty texture. It was listed as truck bed coating or something similar. Sorry for being vague, but I did this back in 2002.
NCDaveD
'96 Windsor towing 2000 Honda Accord