Transfer data from 1 switch to another, wipe old switch?

[MrMrMr]

I've got a v1 switch that son uses. I've bought another switch now (patched) and so want to transfer the old switch to the new switch.

I don't want to lose his data, I'll use the same SD card, accounts etc on it, its basically just to free up the old v1 switch so can "play" with it. Is this possible?

Also then on the v1 switch, do I wipe it all, start afresh, make a new account just for this switch, in prep for home-brew on it? Is that best way? not bothered online for this one or anything.

thanks