This would be the perfect time to go 685. All the parts are bolt on, very few specialized tools needed (torque wrench, and MAYBE ring setting tool). Send the head and cylinder to be reworked, pop in new piston/rings,.......good to go. Disassembly/assembly is not a job for a skilled mechanic (more like "handy puzzle solver"). Once you start taking it apart, take pictures,......of every faze. On assembly, go backwards in pictures. Get Clymer manual on Ebay.
Back in ancient history (before phones with cameras, before "service manuals", before Internet, .......BC!)......we actually WROTE down everything (on paper!), and put parts (screws, bolts, washers) in PAPER envelopes (ZIP locks didn't exist!), with notes, and labeled them "1,2,3.....". Tedious task to say the least. That was for the people like me, that loved machinery, but went to schools for something entirely different.
Go for it,.....you live in 21st century (you have "smart" phone, ZIP locks, service manual, proper tools,.....what else do you want!?
). People on this (and other boards) are friendly, and eager to help. If you get stuck,.....just open a beer, pop on the forum, ask the question, and by the time you are done with the beer, the answer will be here.