How can I transition to a retirement visa in Thailand while currently on a tourist visa?

Easier options than the retirement visa buddy

go to the thai embassy in malaysia to get a retirement visa. come back to thai and use the visa to open a account.

Just opened a bank account on visa exempt stamp using an agent. Easy to do.

You can open a Thai bank account using an agent, on any visa. In Pattaya the service can be had for something like 5000.- THB

*** for a “change of visa type” from an exempt entry, or from a tourist visa, to the initial 90-days Non-Imm-O retirement visa, the police order states that the 800.000.- THB can just sit in the bank account, and you need to prove that the money came from abroad. There is no seasoning needed at this point.

The 2-months seasoning will only be required when applying for the change from the 90-days visa, to the 1-year extended stay permit.

*** however, SOME Immigrations make up their own rules and require the 800.000 THB to have seasoned for two months, when applying for the initial visa. One of these Immigrations, ironically, is Pattaya/Jomtien

You need to ask your specific Immigration on their handling of the “change of visa type” to a 90-days Non-Imm-O Visa, regarding the financial proof with the minimum of 800.000.- THB deposit method

I don't know where you read this information because it's incorrect.

There's no immigration office in Thailand that requires you to have money in your account for 3 months in order to apply for the retirement visa. In fact there is only ONE immigration office in Thailand (Pattaya) that even requires it to be in your account for 2 months. All of the other offices use the normal requirement that it just needs to be in your account and that it needs to be a transfer from overseas. Also the ONLY way you can do this is if you're here as a tourist as you can't convert from some other type of non-immigrant visa to the retirement visa.

It's much better to get the visa from your Thai embassy at home before you travel though, because you likely cannot open a bank account by yourself if you're here as a tourist. You'll need to use an agent to get your bank account and then transfer your money, and then apply to convert to the non-O.