A_S_R, I'm going to do the same thing when I need new tires. I was going to remove the whole assembly (top three nuts, bottom nut and bolt), slide it out together, use a spring compressor to compress it as much as possible, and try and slide it up to the top notch. However, after thinking about it some more, I don't think that's possible as the set ring that fits in the groove also needs to be slid up for the spring perch to sit on. I'm going to try it but I'll probably end up taking it all apart again. My buddy has some air tools so it's much faster.
Curious to find out how you do it, keep us posted.