United Motors Lanka

Hi, how to change the registration of a vehicle here? My car already registered

Please do not buy united motors cars(specially zotye z100). It is a car with a lot of faults. I bought my vehicle 2 weeks back and upto now faults are Speakers are broken, Paint has been applied like applying nail polish, Display is going in the Fm stereo, weird noise comes from the engine, Petrol consumption ( only 5KM per 1L), rexine is damaged in the gear, stain in the engine, head light is yellow, plastic of the aux is broken, doors doesn't shut properly, tuning issues.