Hi

My bike has been out of action for about 10 months, it has tubeless tyres and rims (cross Max ST) and Lust tyres. Now I have never fitted or fixed tubless, but the front keeps going flat.. Can I just put a tube in and be done with it? If so how do you remove the tyre and rim tape? If I cannot use a tube how can I fix the puncture / leak of air? cheers

As a guess… in the 10months you're tyre has gone flat, moved away from the rim and all the sealant has dried up. Now when you try to pump it up the tyre is a little deformed so does not meet the rim exactly and there's no sealant to help (even if the gap was small enough).

How about…
remove tyre
remove any big lumps of dry sealant
turn tyre inside out and leave for 24h to 'reset' bead
pop tyre back on rim with fresh sealant
pump like billy-oh
hope for best.

Alternatively, fit a tube and reduce the faff. More time on your bike.

question is with the Cross Max rims and lust tyres can I just put a tube in? the tyre does stay up for about 1 hr so is still well on, how should I remove the tyre, tape and valve? not dont it before so dont want to mess anything up!!

just bung another 100ml of sealant in through the valve, inflate and spin. It'll be fine.