This was a very difficult part, especially a lot of patience and precision is needed.
I started doing only the PSU but in the end I sleeved the whole pc.
The psu and some tools:
With and without sleeve:
Sleeving should be at 185mm:
Shrink sleeve should be 15mm and put at the end of the cable:
Sometimes I had to open those:
Everything went according to plan but it’s easier to write things down sometimes:
The tool in action:
I even sleeved the sata cable: