VERY lucky you were surfing instead of driving when it went.
Always replace air-bags in pairs - Paddock will do a set of OEM ones for about £130. Delivery takes a couple of days and they come with new clips for the top ends.
Look on this forum for Battenbergs air suspension guide - he gives 2 different ways of replacing air-bags, both of them straightforward.
My top tip is to watch the RH bag as it fills and cut the engine if there is even the slightest sign of it not inflating correctly. With the LH bag, you cannot see it as it inflates, so start the engine (and therefore, the compressor) for literally a couple of seconds, then stop it, go round to the LH and check. Repeat until air-bag is full.
Allow a slack morning for the job, but if all goes OK you should be done in under 2 hours.
LR recomend replacement every 5 years, but if you don't do off roading regularly, you might get away with a bit longer. As soon as they start losing air overnight it is time to replace, as pumping them up every morning is not good for the compressor, which can be around £200 second hand.
