Nut in the middle of my wheel/brake rotor has gone and seized itself on, cause im doin my cvs it makes it pretty hard.

Has anyone else done cvs and come across tis trouble?

the CV hub nut is usually as tight as hell and should be, it is a good idea to try to lift the staked part of the nut before undoing the nut to prevent damaging the cv thread. I use a 3/4" drive ratchet and pipe extention on the ratchet handle (total about 3ft of lever) and then sometime you still have to stand on it to get the nut to crack. If the hub is turning then get someone to hold the brake pedal.