Help fiber trends felted clogs

I need help. I do not understand how to attach the second sole, has anyone made this slippers before?

I haven’t make them recently, but if I recall, you pick up the stitches on the sole with a spare needle by slipping the point up through the purl bumps. Then you do a 3 needle bind-off to connect those stitches to the live stitches on the clog.

So when you do the seperate sole, is it supposed to be shaped like a horse shoe

Yes. Then after it is attached with the three needle bind off, you seam it down the center (length) of the sole, same as you did the first sole.