Just got the Southord jackknife inserts today and finished this project. So taking it apart is as easy as pounding an alan wrench through the pivot pin. Don't lose the pin like I did, took me 5 minutes crawling on the floor to find it haha.
HH still together and the Southord inserts shown above.

HH disassembled. Easy enough!

The Southord picks are a hair thicker, so I had to make the frame a little wider.

After trying to seat the Southord picks into the frame I found out the inner diameter of the Southord inserts are exactly the same as the outer diameter of the pivot pin. No fit!
So I took a 9/64" drill bit and put the Southord picks in the vise. !!; CLAMP the ends with pliers as you drill so you don't bend them all up!

File down the burrs from drilling, make sure they fit in there snug but not too snug. Tap the pivot pin back in gently and you're all set!

So that's finished. High quality picks in a cheap jackknife pick frame.
Enjoy!!