Adding my own NPC's in University Sims 4

So I have recently been watching Clare Siobhan playing Sims 4 Discover University, and I noticed that she has added her own creations of sims and other peoples sims from the library into the university. I was thinking it might be a good idea to do that myself, and have a whole university of modded sims I have created to make it more interesting I was wondering if there was an easy way to do this instead of having to create the sims and physically enrolling them one by one, and if there was a way to create them and add them straight into university.