MY AXLE IS ALSO VERY SLIGHTLY BENT. If I replace the axel will my rear wheels be aligned again or do I have to do more??

Can somebody please tell me if a dealer would be able to align my back wheels? They are out of alignment because I went off the road months back and my brother in law said he needed shims to align it. Can somebody please tell me if it is possible to align the rear wheels and make them straight again.
Thanks


Mark