If you plan on staying longer than 3 months in Thailand, you better advised to get a Thai driving license. This is due to certain insurance companies stipulating in their small print that you are not fully covered unless you have a Thai drivers license. Having a Thai drivers license has other benefits as well, you can use it as i.d, and you can get some discount entrance prices in some of the tourist attractions
Renewal of Thai driving license
Documents needed for renewal of Thai driving license:
Passport (and 1 signed copy of photo page)
Visa page and non immigrant visa page (and 1 signed copy of each)
Two 1 inch photos (available from vendors outside the parking area around the main building)
Your old Thai driving license.
A medical certificate showing that the applicant no underlying disease that may be hazardous
Also the applicant must not be a person of unsound mind or mentally deranged,
validated by a certified physician.
The certificate must be dated not over one month prior to the application.
Submit in the morning and you receive a receipt to pick up in the afternoon.
Fee: 105 Baht.