My Peerless 700-070A Tecumseh Transmission in my Exmark Metro HP Walk Behind Mower appears to have the Shifter Keys worn out. 1st, 2nd, and now 3rd gear are gone. I have an exploded view schematic and step-by-step instructions for the transmission itself: however, I have no service manual and need step-by-step instructions on how to remove the transmission from the mower itself. It appears as though I can remove the cover but I'm quite sure I will need to unhook the axles to be able to pull out the gear assemblies and I'm not sure how to do this. I really could use some guidance so I don't make a serious mistake..Is there a manual I can download? Thanks, Randy @ Central Michigan Nurseries P.S. Should I Rebuild or Buy a New One?