Removing rear springs on the x3 is a pita...
I got mine out by using a long crowbar about a meter and a half in length and was able to find a place to put the end of the crowbar on the subframe and push some leverage onto the upper wishbone by standing on the other end of the crowbar. My friend then was able to pull the spring out. You must detach the lower wishbone from the trailing arm to allow enough movement of the upper wishbone. Very ghetto and dangerous way of doing this the crowbar actually slipped off onetime trapping my friends hands under the spring for a few seconds until I frantically was able to releaser them. No physical injuries just scared for life mentally speaking. So if you use this technique don't put your fingers under the spring... Put the new springs in the same way.