Hello mate,
I completely replaced all my airbags on my drive and refurbished the EAS system. There are plenty of tutorials here and the other 2 classic RR sites, it isn't difficult, just take your time and to one job at a time. Don't buy the cheap crap o ring kits for the EAS block - you'll regret it, I did.
Mine will go from normal height to max in around 3 seconds now - it took a long, long time to rise when I bought the car (all worn out).

The one specialist tool I needed was hook, wire coat hanger, home made x 1 (bend a hook at one end and a loop for a karabiner at the other) You'll need this tool to yank the rusty pins out of the top of the airbags (rear I think).

Easy test for EAS (if you don't already know) - I put mine on high then press the button to lock the EAS (the one that looks like a flat tyre to the right of the suspension height button. Leave it over night or for 3 - 5 days. You'll soon see which one has or hasn't got a leak as that corner will drop.

Not sure if they all do this but when I stop at traffic lights and keep my foot on the brake (no hand brake or parking brake) the car doesn't really move. If I put the car in park whilst waiting at a red light after around 10 seconds it will start self levelling. These days I worry if it doesn't hahaha.

Hope that's of use to you

With the main brakes applied, the EAS is inhibited.

Mukiwa wrote:

Easy test for EAS (if you don't already know) - I put mine on high then press the button to lock the EAS (the one that looks like a flat tyre to the right of the suspension height button. Leave it over night or for 3 - 5 days. You'll soon see which one has or hasn't got a leak as that corner will drop.

Small correction, the inhibit switch (flat tyre symbol) does NOT lock the EAs at height and certainly does not prevent self levelling when parked. All it does is disable the automatic speed dependent switch between normal and highway height (and it can be used to lock the car in access fro crawling around low ceiling parking garages).
If you want to disable the self levelling, which is indeed a good way to find if and where there is a leak, take out either F29 (under the hood) or the timer relay under the seat. Or permanently replace the timer relay with a standard 4-pin relay, so the EAS is only active when the ignition is on.

More on topic, yes, the shop you went to is trying to make a lot of money at your expense. Looks like it can be done a lot cheaper and not everything is actually needed. Especially if you don't have any complaints.

Filip