If it is not off to a degree that requires resoldering, then it can be done through either peening/mauling or forming. This would require specialty tools, and depending where the character sits on the segment, may require addition alignment adjustments to compensate for the angle of the typebar and the effects of the new adjustments; outer characters like 'Q' and 'W' are a real pain to correct--at least for me. Whether you peen with peening pliers or form with roll-benders would depend on the angle of the typebar, if other alignment issues are present, the ring and cylinder setting, and personal preference.

To raise by peening, you would peen the front portion of the typebar just below the point that passes through the typeguide, making sure not to go to the very edge. To raise by forming, you would bend the typebar back with roll-bending pliers. The latter will effect the ring and cylindar setting, also, so it is not always the correct choice. These adjustments should be done very carefully, because a little bit can go a long way, and much of this--especially peening--is destructive editing. Before doing either method, check that there are no other issues, that the typeslug is not loose, and the type is not off by so much that resoldering is required. For more information on alignment procedures, I believe the topic is covered towards the end of some of the Ames Manuals. I would not recommend doing this without the proper tools, and I would practice on a junk machine first.