TurboTax will not split your MFJ tax return into two separate MFS returns. The safest way to handle your situation is to start two new 2022 MFS returns, one for each of you, without transferring any information from your 2021 MFJ return. Enter everything from scratch, as if you didn't use TurboTax for 2021.
Do not attempt to start a 2022 MFJ return and remove one spouse or the other to change it to MFS. It's practically impossible to do that without creating errors in the return that you will not be able to fix.
