Sounds like you could use the trolley jack to get the entire bike in the air and then use your trans jack to raise and lower the rear wheel as needed. A scissor jack should do it too.
Thanks mate...exactly what I've done
Borrowed a bike jack from the welding shop next door and got a mate to assist me, we jacked the bike up, undid all the nuts n bolts, top and bottom of shock and the two bolts on the C-link.
Removed the battery and fuse holder for easy access.
put my workshop trolley jack under the rear wheel and raised it till all bolts came free and shocky almost fell out!
I fitted the Progressive 465 that I bought off 'benm' and jiggled the bottom of it as my mate got the top bolt through then I let the back wheel down till the bottom bolt lined up.
NOTE.. had to source a longer bottom bolt as the Progressive is thicker at the bottom mount otherwise the original would've only been held by 2 threads of the nut.
Everything tight I took her for a ride as benm had it set up, rode real nice n smooth, joins in the concrete road that normally jar noisily were glided over!
Got home and Googled shock tuning on a few sites then jacked the bike back up took a fully extended measurement, also put a cable tie on one fork leg to see how much it rose when weight off.
Then a measurement on the ground with no weight but settled, then a measurement with me sitting on the bike.
Note I backed the rebound setting off to 1 as benm had it set at 5, the site said to back it right off when measuring.
A little arithmetic showed the preload within spec but as I regularly carry bags and a passenger and I dont wanna be screwing with it all the time I wound one more turn down on the preload which brought it to the upper level of tolerance and should drop back to middle with my light passenger.
Then I brought the rebound up to midway the 3 position with my trusty allen key.
Now the fun part!...a test ride to fine tune and have a tinker with the rebound to find a happy medium.
Progressive 465 is a vast improvement over stock.
And 'benm' is a good trustworthy bloke to deal with.
Time for a 2am test ride
leaving the cable tie on my fork-tube to gauge how far my fork compress under my normal riding.
May end up upgrading the front to match the rear if I feel it needs it.