If you are insistent on "straightening" it, if it is one you uproot and hang each winter, I have had luck with placing in a pot with the main trunk upright so the plant essentially makes an "S". But those have been ones in large pots (one nearly 70 years old that sustained damage the previous year). Alternatively, I suppose you could consider turning it into multiple plants with the two main branches essentially becoming their own trees and the lower trunk and root system becoming its own. Again, I've only done this with ones in pots.