This isn't exactly a prep list site but the guy covers a lot of the common D2 stuff - www.discovery2.co.uk

His step by step guides has got me through a few jobs.

Re air bags, I've not found them that much of a problem - I've replaced one each side over the years (an easy 20 min job) and you get the pump up / down / auto level facility. Even when they leak the compressor keeps them going for weeks (months in one case for me) before the hole gets too big.

Buy a couple and just chuck them in the back rather than mess around with springs. They're about £70-80 each on ebay and if you don't use them you can resell them afterwards. I cut the old ones up and used the rubber material to make some mudflaps for my winter rally bike. Probably the best bit of the bike. :rofl: