Remove the wood box. Grab the element at the bends which are farthest from the back of the smoker. Bend up carefully. You don't have to bend much. If the first attempt doesn't fix the problem, try to bend it a little more. I only needed to bend mine once and it made a big difference. I never had to adjust it again.
I never cover the holes with anything, including the wood chunks. I get good smoke even at temps as low as 200 degrees.
Hope this helps,