What information is out there to assist someone looking to reclassify from 74D to 68C?

Get ready for about thirty 100-question tests!

Show up in compliance with AR 600-9. There is no alcohol allowed during phase 1, so start slowing down now if that applies to you. Take the human anatomy correspondence course if possible before arrival.

AIT is forever long so don't let it discourage you (12 months). Also, you will be in a training environment with mostly kids straight out of high school so expect childish behavior with little military bearing.