Donniev, that's a Champion 400. Do a search under the Bellows section here, lots of good information already posted. If it turns smoothly without a lot of grinding noise, there's really no reason to take it apart and you may do more harm than good by taking it apart. They can be finicky to put back together to get the proper alignment that has worn in over 100 years of service. No grease required, add a little oil occasionally and it will splash around to lube everything.
If you do choose to open it up, the top cover has two screws. Remove those and SLIDE the cover toward the back of the gear housing. SLIDE back, do not pry up or you will break the casting.