How can I extend my 60-day visa exemption in Thailand, and where should I go?

To extend your 60-day visa exemption in Thailand for an additional 30 days, you should go to the Laksi Plaza, specifically to Floor 3 Counter K. It's recommended to book an appointment online to avoid long waiting times. You will need to bring the TM7 form, a copy of your passport's data page, your entry stamp, a recent passport photo, the TM30 form, and a fee of 1900 baht. There's no need for an embassy letter for this process.