yes it can be done but its best to remove the forks from the bike and its a good oppunity to change the fork oil at the same time. If you use race techs website it will tell you what spring rate to use, the ammount of oil and weight also.
process is with all clickers out and count how many turns. loosen the top fork cap nut while the forks are still in the tripple clamp. remove front wheel, brake caliper and put aside out of the way (leave the hose connected to the master cylinder).
loosen the top fork cap off when in the tripple clamps. remove the forks. drain all the oil out into a pan use a 17mm spanner on the hex nut between the spring and just bellow the cap and remove the cap. remove the compression tube. (lay everything out on clean rags in order note do this in a really clean work space)....... infact this is quite hard to describe but i will try my best lol.
fill with oil and slide the rebound rod up and down to bleed the air out. there are heaps of videos on youtube how to do this. measure 90 - 110mm (depends on adjustment racetech site has given you from the top of the fork with the tube slid all the way down) fit the new spring and very tickally slide the rebound rod thru the spring inserting all parts back in the same order you removed (remember make sure everything is as clean as possible i like to use electrical contact cleaner cause it evapourates quickly and leaves no residue)do the rebound rod up onto the fork cap then slide the tube back up and do up the cap.
anyway if you get stuck theres heaps of videos on how to do this but i just thought id write a novel here while im on nightshift at work. lol enjoy.
This video shows fork seal replacement but just watch the end half the video when hes bleeding the oil and assembling the forks to get a better idea.
https://www.youtube.com/watch?v=ZSfodbI9EAU&t=422s
