Hextraction - Chân di động cho bảng ưa thích

You need 16 magnets 5mm dia, 3mm height for both legs. You might get away with half of that, but stability might suffer.

There is one downside: magnetic balls get stuck, not really an issue IMHO.

Replace the old Gutter segments with Gutter Leg Segment 5x3mm magnets, use some CA glue. (Edit: legs pictured are about 12mm too long, uploaded correct length)

Insert magnets with tongs (mind the direction of the magnets, both legs same). Optionally add some glue (depending on your printers tolerance)

In case you want to keep your old legs, use Gutter Leg Mount 5x3mm magnets

BTW the orange Gutter Side and End pieces are really helpful, this is the model I used: https://thangs.com/designer/Sashy/3d-model/Hextraction%20-%20Gutter%20Side%20and%20End%20-914312