V220 suspension my first post

[Edwin100]

I've just bought a 2003 v220cdi it's in really good condition albeit rather grubby, pictures to follow It looks like the air suspension is renewed and operating as intended . But... It's so nosey over anything other than smooth road surfaces like new motorway or car park Tarmac. There are some really chattery bangs and thumps form the both ends but I'm going to start at the rear.
I have had the car up on a 2 post ramp when I had tyres all round, giving a chance to inspect/check for the obvious like exhaust, loose bolts warn bushes but they all look good and seemed tight when tweaked with a pry bar.
Im starting with renewing the rear gas struts as they look old old old and the noise reminds me of a passat I had that went through struts for a laugh.
My question is how do I empty the air bags so I can safely jack the arms up to compress the shock for removal install ... I just purchased a pocket workshop manual by Peter Russek unfortunately this illustrates a strut with an air connection. My struts do not have this. Plus it mentions needing to remove 5mm of the air pipe to ensure an airtight seal. Is there a simpler way to safeguard the air bag?
I was hoping to have a go at this Friday by I'm unsure how ...
can anyone help?
Thanks.