He needs to see if he qualifies for Rights of Residence, by virtue of the length of his residence in the UK, or, if he has been in the same employment for 12 months, whether he qualifies for leave to remain under the Ankara Agreements.
Just a quick note, it may help you more if you posted on another forum, such as
http://www.ukresident.com/ The UKYankee board is focused towards US nationals coming to the UK, and as such you will only have a few people (me, Garry) who would be able to assist in any depth, as most will not have experience with things such as the Ankara Agreements, and only a few will know about Rights of Residence. The other board will have many more people who will have been in your position, and will have first hand experience. And Garry and I are there too.
Vicky