I have an HP LaserJet 4200 envelope feeder that has the main feed rollers needing replacement. I can't, for the life of me, figure out how to get these things off!! picture: http://www.oia.mines.edu/printer.jpg

What problems are you having? Those rollers don't look like they need replacing. Have you tried just cleaning the surface of the foam or rubber? Manuals HP LaserJet Envelope Feeders http://h20000.www2.hp.com/bizsuppor... Parts LaserJet 4200 here: http://h20141.www2.hp.com/hpparts/S... There is only 1 service manual for the whole series - buy it for $66 USD - presumably it's got instructions for maintaining the envelope feeder included. Email HP if you want to find out for sure. E.g. manual - Keyword search for: manual or Category: Accessories feeder parts - Category: 500 Sheet Feeder Assembly parts diagrams envelope feeders here: http://h20141.www2.hp.com/hpparts/S... If that's of no help, try phoning a place that servicves HP Laserjets.

If you wanted to get the rolloers off the shafts, that may not be possible. You may have to get the whole shafts with the rollers on them - see the feeder parts lists.