Mate the torsion bars are very simple to unwind. Just jack the front end up, to take the load off the torsion bars. Then undo the locknut and slowly undo the adjuster bolt until all the tension is released and the bolt is loose. Then you just have the wiggle to the adjuster bracket out of the back end of the torsion bar (hit with rubber mallet or similar) and then you just slide the torsion bar back slightly (may take a bit of force to unseat it from where it mount to the lower control arm, should be able to be done by hand though). Once the torsion bar is unseated from both ends you can just manoeuvre it out. Just remember how many full turns it took to get out so when you re -install you can get it back to the same height, also take note of where the adjusting bracket sits in the crossmember because when you re-install it once it is tightened it should tuck up inside the crossmember where it is protected. If you need to adjust after cos its not the same height then one full turn is usually equivalent to about 5mm in height increase, this is what it is for my HD torsions, yours if standard may be a little less as the spring potential will be a little less due to it being a standard bar and being older.
I WOULD NOT simply undo the crossmember bolts as the torsion bar has a huge amount of force applied to it to hold the vehicle up, and even when you jack the front end off the ground there is still a large amount of force being applied to the spring.
However I have no idea if the amount you could lower the crossmember by would help you take the transfer out, id just take the cross member out fully so you save time messing about.