To get the rack out of the housing you're going to have to remove the governor housing from the back end and then remove the injection pump housing from the engine. There are pins in linkages on each end of the rack which will have to come out to disassemble everything.
Once the injection pump housing is separated, remove the pumps from the top, being careful to keep each plunger in its pump and keep everything clean. Once the pumps are off there is a "stop " pinned onto the rack bar at the back end. If you remove the tapered pin and the stop, the bar should slide out of the front of the housing, possibly taking the bushings with it if it's really badly stuck.
Thanks for the information on how to remove the fuel rack. The tractor is in northern California and I am in southern oregon. It'll be a couple weeks before i head that way again. Looks like I'll have plenty to do while I'm there! I will keep you posted as to the outcome. I may be in need of a new fuel rack -- any ideas on where one might purchase a used rack for my D2 5J?
Thanks again!
old5j