raise disco 3 air suspention without engine running

how do i raise the air suspention if the engine is dead? and hasnt been running for a while? can this be done by using the key? if the batery has enough charge?

engine cant be started

Pretty sure engine has to be running?
Is it just to move the car? if so and you can get to the 4mm pipes on top of the air bags, I would say you could cut the pipes and add a valve so you could pump each bag up, bit like the get you home range rover kits that used to be for sale.

Thinking jack one corner of car up, fit axle stand, cut air bag top pipe leaving a 50mm stub, then buy these, https://www.ebay.co.uk/itm/4x-Flexi...950523?hash=item1efd13c67b:g:NiQAAOSwR5FdEkh1, cut the female end off, slip rubber hose over 50mm stub and secure, then blow that bag up?

If you have enough battery just pull the suspension relay, number R7 in the engine bay fuse box. Jump the two large terminals together with some decent thick wire and the compressor will run. Note the two larger terminals not the two smaller ones are the ones you connect together !
Works, I tried it on mine last week. Hope this helps.