I know you have a W123. others may not.
The fronts you WILL need a compressor.
The rears, remove the Shocks.
Remove the calipers and wire them up to the Sway bar. this is to keep from stretching the brake Hoses when lowering the Diff and the Trailing Arms.
Place a Floor Jack under the Differential.
Remove the 4 13mm bolts that secures the Diff mount to the body.
Lower the Jack, and the Springs will fall out.
Charlie