Yep defo need to let the hydrolastic fluid out - if you don't the unit will most likely 'pop' as you take all the weight off it. There's 400psi pressure in them things! However once you do let it all out they are extremely easy to work on as unlike springs there is no chance of it springing up and chopping your fingers off once deflated.
bugger, will have to get russel to do that then!
I have a pump and offer a mobile service to people in the local'ish area
I also fitted lowering pins to me F along with the Gaz adjustables around about a year ago. PM me if I can help at all