Air suspension bag change - deflate?

HELP!! Have to change air bags on a 2003 TD5 in Kenya.
How does one deflate the units to remove and change them without using 'Testbook .... which, obviously, the local 'authorised Land Rover agent' doesn't have?
Can one just disconnect the pipe? Or will this confuse the computer or leave the car sitting on its bump stops?
Have looked in the workshop manual but no help there. Have searched high and low here too.
PLEASE HELP.

(Why do L.R. do this sort of thing to their poor loyal customers? Do they ever wonder why Toyotas etc. now rule the market out here ??????????????)

jack the wagon up off the deck so the wheels are free.take key out of ignition and un doo compressor tank nipple.this will let the air out.Once done remove air bag and fix.DO NOT turn ignition on till all parts are replaced and that way the ecu wont kbnow and every thing is hunkydory.

Beast of Bodmin,

Many, many thanks for that very succinct answer. Makes complete sense. Why the %$£! they seem to insist, in the manual, on using their 'Testbook' to deflate the damn things, God only knows.

rgds

Beast o Bodmin said:

jack the wagon up off the deck so the wheels are free.take key out of ignition and un doo compressor tank nipple.this will let the air out.Once done remove air bag and fix.DO NOT turn ignition on till all parts are replaced and that way the ecu wont kbnow and every thing is hunkydory.

Click to expand...

where is the compressor?