The racks might swap over, but the UJ between the column and rack pinion is different so you'd have to also swap the steering column, I doubt EP82 and EP91 steering columns are interchangeable.
I have a suspicion that the EP91 has a wider front track than the EP82, so you might need to swap the track rods over as well (that's if they're interchangeable?).
The pump should swap over without too much trouble, but the EP82 powersteering pipes probably won't suit the EP91 engine bay.
In all honesty it's probably not worth attempting. If your friend want's power steering in their EP91, they're best off finding someone who's breaking a Glanza. If you want a non-assisted rack in your GT you'd be best off sourcing a steering rack, UJ and column from an EP80 or EP81.