If you have luggage go to the queue for a meter taxi. If travelling light you can take the train/metro BTS. Ticket Agents are helpful if you can't figure the map. Takes about the same amount of time as a taxi unless it is raining or rush hour. Make sure you change some money at the baggage claim area to pay for your trip. A small amount $50 is plenty. Better exchange rate in town at Super rich
I have given lease agreements to numerous tenants to open up an account. They do not have to be for a year. I also gave them copies of their TM30. They all opened accounts successfully in Samui without an agent.
Bangkok Bank should do it with TM30 from where he is staying and a lease or rental contract of some sort. Can be only a couple of months. They need an address.