Well, i am in the same position so i think i may help you. In order to work in UK he must be registered with tha HPC and the CPS organisations in order to be legal and accepted to jobs there. This prosedure takes long and needs a lot of paperwork. Also there is a chance of not beeing accepted. For me the best way is to take a course in UK so as to gain practice there and upgrate his deggree and then it would be easier to register and work there.