You can do it yourself but don't expect it to just work, you may need to do some fine tweeking to get a good signal and you will have no idea just how good it will be in the wind etc.

In your position and with the problems you seem to be having with the tree it would be much wiser to contact a local installer to cone and put it on a meter and get it as far away from the path of the trees as you can, this could even mean fitting it up on a pole or the stack.