I imagine its just a bunch of drilling.
Mount all the arms up to the axle
Push the plate up
Mount the arms on it
Bolt the t-case up
mark where the plate holes are on the frame.
Drop it all
Measure mark distance from stock holes
Drill the plate to match, using the marked holes to stock holes center to center distance.
Something along those lines should work.
Or you can drill the frame to match the old style skid. Drill right through, use a spreader plate on top of the frame and attach everything with about 4" long bolts.
One of those should do the trick.