For figures that use PBMCC_## channels, I use D3D's "Spawn FBM" py script to spawn the morphs from the magnets, then svdl's "SpawnCharacterP6 update" py script to make the INJ/REM pair. "Pozers Little Helper" (PLH) is another application I use for making INJ and REM files. All the above are free.

You could also look at PMD injection, there is a tutorial at nerd3D.

P.S. if you make morphs with magnets, you may be interested in my "MirrorMags32" to make mirror symmetrical magnet pairs.