You bought an 07, UK GT,without any manual ?, If you bought this from a Dealer get him to supply a full pack including
an owners manual. Dont know what your adjusting but its not the service intervals...they are set by either the time
like once a year or the miles you do, I do a P1 service on mine every 4,000 miles, Change Oil, filter, and check everything else
and replace things like brake pads, etc if they need doing...check the Forum for Service Intervals and P1, P2 & P3 servicing.
Good Luck. :thumbs: