Your painter probably installed the bar backwards, it is easier to install that way (my painter did the same thing) but the hood won't stay up. No worries, it is not that tough to correct.
As long as you are going to tackle this, you might want to get a new torsion bar: for $35 or so you can make sure you never have to tackle again. Don't know if anyone else has had to do this, but mine had weakened to the point of not holding the hood up.
To R&R first secure the bar in it's fully-tensioned position by using a fashioned "s" hook. Put one end of the hook in the hole in the side of the hood that orients directly above the end of the free end of the torsion bar. Hook the free end of the bar in the hook so that it lays nearly flat against the underside of the hood.
Protect all edges of the hood, fenders and nose. I use heavy painter's tape, it does not provide much impact protection but it will not harm the paint.
Remove the two bolts from the hinge on one side of the hood. Remove the hood by sliding it out from the other side of it's attachment but leave the hinge on: this will make it much easier to realign the hood when you reassemble.
Lay the hood upside down on a soft surface (carpet) that has been covered with a cotton barrier (cotton or flannel sheet). Put another cotton towel in between the torsion bar and the underside of the hood for more protection. Carefully release the end of the bar from the "s" hook, remove all of the screws from the plastic bar guides.
The bar end will now point towards front of hood. (Actually, if it was installed backwards then it might point rearwards, but you would have already realized that!) Now the tough part: to get the angled part out of the slot in the right side of the hood you must put tension on the middle part of the bar (that is why you put the towel there). With enough tension you can then slide/pull/lift the right side of the bar from it's hole.
The rest is intuitive, just be very patient. Make sure that when you reinstall the bar you begin with the free end pointing to the front, (don't forget to thread the plastic mounting brackets on in the right order) then reinsert the hooked end in the right side of the hood by again bending the bar in the middle (with the towel to protect the hood) and coaxing the hook into the hood.
Best of luck,
g
'64 230sl, fully sorted out...ooops, spoke too soon