There is a good kit of felts etc. that you need along with great instructions. (It's in other threads on this site - I can provide details if you are interested). If your lathe is in semi-decent shape it really doesn't take that long to do and you don't have to do everything at once - unless you are really trying to do a "restoration" ie. paint etc.
I was able to completely dissemble and rebuild my tail stock, saddle, apron - everything accept the cross-slide handle (was working fine and did not want to come apart without messing up spanner nut) in 3 or four days tops. So a concerted effort but only 4-6 hours a day.
I did the headstock on another weekend.
I have not done the quick change gear box.
It was scary taking everything apart but well worth the effort to clean and get everything running smoothly. I fixed up a few minor annoyances along the way.
That said - it was a good 8 years after getting the lathe before I tackled it!