If the student is able to convert their tree out of MEGA (is MEGA even accepted for publications now? Recent experience says "No".) into a Newick file format they should be able to use any number of tree editors (as Alice has stated already).
For a tree editor, I would recommend using Figtree. It's my favorite. I think the student will find it easy to use, flexible on many platforms (not unless they have issues with Java) and you can go from rooted to unrooted tree in seconds.