You either need 2 new springs or new dampers for the front, depending on how you wanna go. New springs will mean itll be stiffer but in turn wear out standard dampers a lot quicker. The torsion bar is simple a matter of jacking rear of car up, removing back wheels, pull out torsion bar both sides, jack arm or hubs up (depending on type of torsion bar) to however low you want it, put torsion bar back in either side, put wheels back on, lower car, see if its low enough, or in my case too low and end up raising it a little!!
Theres a guide on daz-uk.com for open torsion bars, mine was enclosed so if you do intend to do it and find yours to be enclosed, simply jack the hub up instead of the rear arm.