My cable provider stops all programming and streaming to broadcast Amber alerts. For crying out loud, I'm inside my house watching Game of Thrones. But yet they think I am the one that can be on the lookout for a gray Mazda?
A project that is a complete redo is the wrong approach. Just look at the decades-long IRS modernization project for an example of how that approach has never worked.
Take small portions of the process and update them one at a time.