Yes, it's a long spring that really doesn't want to be compressed whilst attempting to refit retainer with oily hands. At all.
Apply a constant pressure with twisting action and swearage. Retrieve spring. Repeat.
Insert picture of perfectly formed Vx grey sealer gasket here. Whoops.
Refit cover while holding new /old pump gears in place without disturbing 'gasket'.
Refit all six hex screws without dropping any on your head/in drainer or watching them roll away.
Torque (wiv and actual tool an' everyfin') and wait appropriate amount of time (12 hours) before starting. Or 45 min because I need to load workshop.
Check for leaks and oil pressure - none yet and some.
Check oil pressure after sustained high-speed run (hahhahahahhahah - 'high')
Check for leaks on Monday after minor Torrey Canyon on drive
Replace turbo with another one (about 2ish mm radial play!)
Wonder if odd clicking noise is vicious fan coupling about to seize/explode.
Repair drivers seat base webbing.