Unless you are pretty much a kitchen table gunsmith I wouldn't go any further than remove the clip,remove the bolt,remove the takedown screws and lift the action out of the stock.You should be able to do a good cleaning from this point with a soft brush and maybe carburetor cleaner.Don't disassemble the bolt,just flush it good til the cleaner runs clear .Some of these old Marlin actions are put togather with rivits and E-clips that can be a mess to reassemble and some springs need a special jig to reinstall.
Please forgive me if I'v under estimated your ability,but after all,you ask.
Please forgive me if I'v under estimated your ability,but after all,you ask.