Hi,
So these shocks are held together by the spring preload adjuster system at the bottom of the unit, you have a bottom sleeve with the adjuster wire handle, then you have a top sleeve above this under the bottom of the spring, if you compress the spring under this top sleeve there are three ball bearings that run in a rising track in the shock body to facilitate preload adjustment....but these three ball bearings also retain the spring, so with the spring compressed and the top sleeve raised the balls will fall out and the spring is free to remove. Long ago I made a spring compressor for ducati rear shock springs utilising a heavy duty silicone cartridge skeleton driver gun, just cut a segment out of the front flange of the skeleton gun big enough to slip through the bottom coils of the spring and big enough to clear the shock body, put a rubber pad on the plate end of the driver rod to save damaging the top of the shock mounting eye ..........ratchet the skeleton gun up just as with a cartridge fitted and this will compress the spring ......works a treat

just be careful to use a well made skeleton gun, a cheap rubbish one will just break unexpectedly and possibly injure you
Cheers,
George