How do I extend a Tourist Visa in Thailand and what transportation options are available?

Just returned from my visa extension.

Some tips for who needs to do the same.

As was written by Graham Seal to me (thank you pal) here how it is working:

"If you bought a Tourist Visa from a Thai Embassy/Consulate outside Thailand before you entered and were stamped in for 60 days you get your extension from the main Immigration Office at Chaengwattana, Building B, Counter J. If you entered on visa-exempt and were stamped in for 30 days, you are going to go to IT Square, Laksi Plaza (3rd Floor) temporary office, just next to Lak Si station of SRT Dark Red Line. All extensions cost 1900B."

About transportation to Immigration Office, i took BTS till Wat Phra and then Pink line to Immigration office. They give free ticket for this line, i think also because it's not finished yet, there were issues during the way on and the way back. It's possible that you must change train at National but hopefully there are nice officiers who helps in case you need.

From Government complex stop (pink line) you can walk for 1.5 km or take the bike.