Dave
It's the transition from in the van to out of the van where trouble is most likely as you cannot get a pure straight lift.
Consider arranging a narrow sturdy, well supported, table (two scaffold planks?) outside the van door(s) onto which the heavy bits can be worked to make the transition. Once on the "table" there will be easy access from both sides for a straight lift.
Its the twist that does your back in!
Obviously minimise vertical shifts. No point in putting the head right down on the floor when it only has to come back up again. Clear some bench space.
Consider arranging intermediate support for things that will end up at floor level. Breaking vertical lifts into foot or so steps so you can change your grip and angle of back as appropriate considerably reduces the strain.
Advance prep is the key.
Don't be afraid to do a mock run with a cardboard box or other lightweight item of similar dimensions to verify that the move will go safely. I know of a guy who did just that and tripped mid move during the "edge sideways'n turn bit". Jabbed himself in the back with a door handle I think. He reckoned looking silly for minute or two under a cardboard box beat the heck out of looking silly for a month or two in plaster casts. Let alone the hassle of finding folk to drag him out from under an offending heavy object.
I think the parts for this are in the dangerous zone. Much heavier and you have to get serious with proper lifting kit. Much lighter no problem.
Just seen the superb pictures from Mike which really makes it clear what you will have to deal with. Straight lifts will be the order of the day if manhandling. Young Clive would have dived in. Old Clive knows better and would get a crane.
Clive
Edited By Clive Foster on 03/10/2020 17:52:34