Sheesh. A spring compression tool might be a good idea to have on hand.. in case. But why? A spring compression tool would be needed if the spring is taller than the space needed to fit the new spring into correct? So if there is any possibility that this is the case have one on had, just in case. Rent one for free at autozone, since you will need it very rarely and I would argue you won't even need it at all.
If done properly you will NOT need it.
See the pictures at:
http://www.expeditionexchange.com/retainers/install.htm
http://www.expeditionexchange.com/disco2frontcoils/
http://www.expeditionexchange.com/disco2frontcoils/DCP_1098.jpg
Granted, the pictures above are not a D1, but it will do the same thing. Without sway bars and shocks the spring will just come unseated from the top. In the rear mine does this even with the shocks every time a tire hits a big hole so I have cones.
NOTE: DO NOT use the high lift for this as shown above, place the vehicle on jack stands mounted to the frame. Almost as high as you can. Then lower the axel with another jack (preferrably floor jack), then you will have your bottle jack just in case you need to press your front axel down to get more clearance for the spring. Do the rear and then the front. The rear are easier.
Obviously the rear needs no compression at all. The spring will fall out. Thus the market for spring retainers and cones.
The front might be different. Sometimes you might need to press down on the axel since the radius arms and other front suspension components bind. However this can be done trivially with a strategically placed bottle jack, but I did not even have to do that and I have done springs 3 times now.
Watch constantly as you drop the axel. Do not over extend your brake lines.
It is a piece of cake. Since you are a beginner, just remember patience.
Good luck!
Brian
If done properly you will NOT need it.
See the pictures at:
http://www.expeditionexchange.com/retainers/install.htm
http://www.expeditionexchange.com/disco2frontcoils/
http://www.expeditionexchange.com/disco2frontcoils/DCP_1098.jpg
Granted, the pictures above are not a D1, but it will do the same thing. Without sway bars and shocks the spring will just come unseated from the top. In the rear mine does this even with the shocks every time a tire hits a big hole so I have cones.
NOTE: DO NOT use the high lift for this as shown above, place the vehicle on jack stands mounted to the frame. Almost as high as you can. Then lower the axel with another jack (preferrably floor jack), then you will have your bottle jack just in case you need to press your front axel down to get more clearance for the spring. Do the rear and then the front. The rear are easier.
Obviously the rear needs no compression at all. The spring will fall out. Thus the market for spring retainers and cones.
The front might be different. Sometimes you might need to press down on the axel since the radius arms and other front suspension components bind. However this can be done trivially with a strategically placed bottle jack, but I did not even have to do that and I have done springs 3 times now.
Watch constantly as you drop the axel. Do not over extend your brake lines.
It is a piece of cake. Since you are a beginner, just remember patience.
Good luck!
Brian