Basically...every 2 years the belts need to be changed. Do this no matter what the mileage.
You can do this yourself, but unless you are VERY confident with engine mechanics...I would advise you take it somewhere and pay a pro. You also need to have the valve clearances checked and if necesary adjusted. Also worth getting your rockers checked at the same time.
You have many places to choose from, but as the bike is out of warranty, I would advise you take it to one of the better independant specialists, many of whom frequent this board.
Cornerspeed (Nelly), Moto-Rapido (Wilf), Baines Racing, Techmoto, Snells...to name but 5...take your pick. They will work outa little cheaper than the main dealers...but if they find a rocker or two needs replacing...gulp...hold onto your wallet!
Where abouts are you in the country?
The interval servicing (every 12 months) you can do yourself, with relative ease. Usual things like fluid changes, checking this and that...no real problem if you have a basic understanding and can handle a spanner or two.
Threaded Mode