Yes you can take them off without removing the spring but it will not be the easiest job. Even if they are not corroded rebound needle could be stuck( seized ).Is it possible to get to the stepping motor to clean/replace without tearing the entire front strut apart? I have changed out springs on other BMW models but not the K1200/1300 yet.
Apply plenty of heat to lose the green loctite.
It would be good to grab the round part in the vice with sof jaws.