I don't believe they are adjustable. I think you can remove them by pushing in hard at the pivot point while turning past the stop in the "UP" position. I would remove one and see if it can be adjusted once taken off. Maybe you can adjust the angle, but surely not the height.
A good seat cushion would be the next consideration. Just make sure you can still reach the pedals.
If all is hopeless, you might be able to purchase off-set or adjustable armrests from the OEM supplier. For our 2007 it was http://www.paulsseating.com/
Do you have the original seat tags? PC-USA can help with your seat supplier. Those armrests are not expensive. They cost me $20 a piece (or was it for the pair?) when I ordered my 3rd captain seat by the entry door. Keep in-mind that offset armrests would stick out forward when folded upward.