indexing cam has slipped forward on my printer

I thought that the plastic belt that is attached to the upper back of the printhead caused it to tilt forward which caused it to scrape the paper track as it moved from left to right. After reading a possable solution, i now need to know where is the indexing cam located? Can i get to the it ? Can i re-adjust/fix it? What tools will i need? Is there a video or diagram showing how to make the repair?