@captainflight
A few people seem to have managed to renew the RTR A on the basis of 5 years . You should give it a shot , but otherwise you need to pass Part 1 again
@captchopper
There is no need to register online to renew the license . A simple cover letter , the application form for renewal ( COP 23 ) and self addressed envelope ( to send the new license ) and other documents like logbook copy , letter from flying school/employer saying the hours authentic is all you need
Of course you will have to send the application to the same RLO that issued the original license