I think Elka put too light a spring on my shock. I weigh 200 lbs and they put in a 500 lbs spring. It sure seemed like I had to crank the crap out of it to get 30mm of preload.
So, is changing springs as simple as spinning off the top ring and somehow releasing the bottom clip or is there special equipment necessary?
At 200 lbs without gear, a 500 lb spring is where you should be,
A heavier spring will only serve to make your ride harsher, The goal is a plush ride, with total control.
If your sag is set properly, determine the middle settings on your rebound and compression, and ride your bike,
Then work on one of either rebound or compression at a time until you find the sweet spot on your shock for you and your bike,
It will all be good,
BTW: if I were riding on the track I would be looking for the 25 - 30 mm sag, and I prefer for closer to 30 so that the suspension is more pliable and forgiving.
On the street, I would look more like 32 - 35 depending on if I was into commuting or twisties as my main target,
The spring, as has been stated is not particularly hard to remove, or change,
Enjoy the ride, and best regards,