How can I obtain a B visa and work permit for conducting business in Thailand for a foreign company?

Hopefully this'll only be a quick question.. How would someone go about obtaining a B visa and work permit to conduct business here, for a foreign company? Example: working here online running there own U.K./ US company or working for a Chinese company teaching online.. ?

( it has already been discussed as to whether B visas are needed or not. My question now is only how to obtain one IF I wanted to try)

Thanks in advance