your config.yaml stays the same, you’ll want to back up and remove all the other files from the flash.
If you are using a V1 machine, you can get the initial setup of your machine from here:
Latest version of the WebUI v3 for FluidNC can be found here:
If you are using custom macros, you’ll need to redefine them, but the V1 starter files will have some examples to help you.