Having just spent a week stripping down my reels (why do I have 17 of the buggers?) and servicing them ready for the winter, this is how I do it.
Reel schematics are easy to find on the web, however, some of the schematics on American sites are for American models and may not be identical to the European models (Abu are very good at that).
I use Napier Gun oil in a spray can to clean them, it contains an anti corrosive and is pretty good as a releasing oil on corroded screws.
Beg steal or borrow a good set of screwdrivers/bits that actually fit the screws properly ( I use a set of gunsmiths turn screws I inherited)
Be careful using brake cleaner - contains isopropyl alcohol, which can and does melt some plastics , some reel bearings have have plastic covers! Use lighter petrol for cleaning bearings.
Buy proper reel grease - something like Cals universal drag and reel grease, it does not dry out and (this may sound daft, but it's not) is waterproof.
Take your time, when taking springs and spring clips off, use a big see through poly bag to work in - it will save bloody hours crawling round the floor looking for the clip that's just gone ping
Lay everything out in the order you take it off makes reassembly easier.
If stuck, ask on the forum!