How to properly reno TTTF to St. Augustine

north texas. I've searched around but couldn't find anything comprehensive. Do I need to do a sod cutter or can I nuke and till it? I was thinking of doing this in February or March (soil temps will reach 70 by march). If I have a problem with common bermuda is there something I can do about it at this time? I'll probably do a proper ph test before this, anything else I should do to amend the soil? I will likely do humic and sea kelp.

Any general tips and process that anyone could share please and thank you!