I used the internal compressor on my 82 Regal about 30 years ago, and I believe I couldn't get the compressor out after putting the nut on the lower ball joint.. It was so long ago but I think I had to take the nut off again and use the floor jack ever so gently to keep the coil spring somewhat compressed. Replacing replacement style front springs on a G body GM is brutal.. There's really no cup inside the upper arm, just a bunch of triangle tabs that look like they were made with a huge old school beer can opener..