I am an older, resourceful DIY. I have gotten to be an older DIY by not going too far. Remember, there are old pilots, and there are bold pilots, but no old, bold pilots. I wouldn't touch a hot service line.
I don't see how you can do this yourself without having the power off for quite a while. Getting the power company to cut the power, make the change over, have the inspector come approve it, and the power company to restore power all in the same day will be tough. At least some of those you will need cooperation from will do all they can to keep you from doing it yourself. So it is 2 in the afternoon, the inspector says you have to change something and the electric people quit at 3?
As in the first answer, you may find it expedient to scrape up the money to pay to have the meter to box work done professionally.
I might go further with the generator mentioned in the first answer. It won't be cheap either. Start with installing either a double throw switch or an interlock on the new panel. For more details on this, I have summarized the options at https://www.askmehelpdesk.com/electr...se-123290.html
Square D and GE sell interlocks for their panels, otherwise you have to go with a third party. I think the generator panels are very expensive for what you get.
One you have the generator ready, have the power cut, and you can manage without it until the pickiest inspector is happy. Of course, you will be already to go whenever a power outage happens too.
You can get advice here that will ease satisfying the inspector.