I have gone through my workshop manual a few times now on trying to understand how to remove the units intact. The manual says to loosen the bolt at the lower wishbone and then undo the bolt attaching the to the trunion lower wishbone mounting but nowhere does it say that the spring etc has to be supported. Normally these are widowmakers so I just want to make sure that I am doing it right. Any comments or suggestions would be appreciated.
I know that struts can be removed easily but normally they are still under some load.
Get the car on jackstands, remove the road wheels which will let suspension go to full droop. The spring is captive on the shock; loosen the bottom bolt thru the trunnion and remove the bolt through the lower shock bushing. From inside the car, up in the footwell, there's a rubber plug, remove it, and you'll see the head of the long bolt for the top pivot bolt; the nut should be on front. Take a photo so you know how all the bits go together; there's a fitting welded into the front and rear of the box, a spacer, maybe a washer or two depending on the clearance to center the shock, and the anti-roll bar vertical all pinned together. Get a helper to hold the box wrench on the nut, and ratchet from the inside (you'll probably need an extension on the socket).
100% soaking with PB Blaster or your choice of release liquid the night before. loosen the bolt. Pull back, and catch the bits as the bolt comes back. The shock should be free.
When re-assembling; use anti-seize on the long bolt. Torque to book specs when re-assembling, but it has to be done with the suspension compressed with the weight of the car on the hub(s) so the bushings are loaded neutrally. I lowered the car onto jackstands under the hubs, put 150 lbs of weight in the front luggage, and torqued the bolts. Others have other ways of doing it; if you have a lift, it's a bit fiddly, but, a necessary step.
Just my suggestion...but again, the shock and spring are a captive pair.