I do not know exactly what bus. But I have done it from Chiang Mai and Chiang Rai. You have to go to bus station two I believe in Chiang Mai. Take the bus to Mae Sai. The bus station in Mae Sai is a little ways from the border. I have walked and taken a tuk tuk. So it’s your choice. Just tell them the border and you will be fine. It takes about 5-6 hrs by bus depending on stops may take more. But you just cross over and they will take your passport and give you a piece of paper to pick it up when you cross back.
Just got to Mae Sai and go to Burma. Should be about 500 baht depending who you get that day they may or may not charge you. They will take your passport and keep it until you return but it’s simple and easy. You can only go over land twice when doing a visa run, but unlimited by air.
Yes but to my understanding you can go get a new single entry visa from a thai embassy outside of Thailand and get another 60 days and the another 30 form thai Immigration.