To gain access to the end of one of the torsion bars, you will need to remove one of the anti-roll bar end plates. However, when taking into consideration the easiest directions to withdraw both torsion bars, it will be best to remove or rotate both end plates.
The end plates come free from the anti-roll bar with a little elbow grease. You will find it easiest if you start with the near side end plate, as this will have a hole in the middle which will allow you to attach a bolt straight into the anti-roll bar, and pulling it outward will automatically remove the end plate from the other side. However, you can miss all of this out, if you can manage to slip the likes of a screwdriver behind the end plate and gently easy it off the anti-roll bar. Once you've done this, you can then just rotate the anti-roll bar, moving the end plates away from blocking the access to the torsion bar bolts.