Hi!
You would search for the accounts on the main search page and make them your selection. Then go under your quick actions drop bar and there should be something like consolidate or merge....then it will take you to a page that allows you to pick the parent record (typically I would pick the one that has the most information in it already). Hit next. Might error for you to clean some things up...for instance if it is a contact that you are merging and they have students associated on more that one account you have to delete the students for it to merge and then add them back. I recommend before deleting you take a screenshot of the page and then merge.
