to remove any hose it can require patience and just pushing a little bit with your fingernails, a little all the way round and continue moving all the way round until it comes off. If it really is impossible then buy more than you need. Use more than enough length and when you reuire to move it use a stanley knife to slice from the join into wards the glass/metal connector so that the hose isn't a continuous seal anymore.
Then when the hose is too short, get a fresh length.
You shouldn't really need to be removing CO2 hose that often. A couple of times a year at most.
AC
AC