My Nasal Bones Have Shifted to One Side After Primary Open Rhinoplasty, is this Easily Fixable?

It depends on how much deviation there is, versus just an overprojection of bone and / or cartilage. For a full deviation, rasping/shaving is unlikely to make a major difference, although can certainly help things.

I would need to see photos of this to determine if you are correct. If indeed the bones are over to one side, they need to be refractured into the center.

Malaligned nasal bones may require surgical osteotomies or repositioning of the bones, however it is true that mild assymetries post-operatively can be remedied by a non-surgical shaving technique as you described. Certain patients are candidates for injectables which can camouflage irregularities. True residual bumps may require a return to surgery. It is common that revisional rhinoplasty is necessary in up to 10% of patients. 

I you're correct and the nasal bones have shifted, it will be necessay to reposition the bones. I cannot answer your question without pictures.