I have done a full rebuild on an 039. It’s like anything, a little practise goes a long way.
Once you have rebuilt a few of them, it will be second nature.
Though, there is no denying they are a poorly designed saw for disassembly and reassembly,
The 020 and the 076 are two other saws that were poorly thought out. It seems from the saws I have done total rebuilds on which date from the 50’s to 2010s the pro saws from the 80’s -2000’s were the finest saws to work on.
The 07 from the late 50’s I have done was fairly good, the 08 was ok, though their clutch cover design is woeful, their 076’s too were fairly ok, but a few aspects just made the process more involved than necessary. That takes you to the 80’s. 026, 034 & supers, 036’s and up absolutely wonderful. Then the 90’s with the 260, 360 and up etc, excellent too. I haven’t worked on any newer models from around 2010+ but from what I have heard and seen, they go down hill once again. 261 is known for being much more involved. I presume that’s the same for other similar aged models 362 ect.
Though again, any saw, once you have done it a few times, is second nature.
On a personal level I must admit, I won’t touch another clammy (unless it’s to help someone out) especially the 029 / 039 series.