You need to push the crank out to the drive side. When using a square taper bracket and crank, this is trivial. You just put a spacer which could be one from a cassette. (Trials, at some level can be done even without a spacer - you just screw out the cartridge/cup a bit out.) I have no experience with the outside bearings, but Chris King sells some fit kits, that could include identical spacers. The shim for the adapter is trivial too - just a strip from a tube. If you want to be fancy, you cut one from an alu sheet. There is some bolt there that seems to interfere with the adapter - do not know what that is.

Quite honestly, if just those above are problems for which the skills of the mechanic and yourself are not sufficient, I do not see how this project can converge in a reasonable time.