Okay,
@Mau****
, like Samwise, &
@Dun***
, said IF you have a 2 year temporary thai driver's license you don't need your german license for anything.
You need a medical certificate, proof of residence (either a valid work permit, certificate of residence from the immigration office or a notarized letter from your consulate), your passport and your current thai license.
@An***
, asked what visa and/or extension you're currently on, and that's important too.
As far as I know you can't get a 5 year license on a tourist visa. They'll just give you another 2 year one. :/
Be advised that you wait until AFTER your 2 year license expires to go get the 5 year one. Going before it expires only gets you another 2 year license.