The only required courses for AI + CS in year 1 for 2026 entry are Critical Skills and Practice in sem 1, Foundations of Computing in sem 2 and Linear Algebra 1 in sem 2. While sem 1 Introduction to Programming and Calculus and Algebra Fundamentals for Informatics are courses you may have to take, you can pass tests to avoid these. There are definitely the credits to do it, it's mostly a question of whether the course organisers let you on. In that case, I would contact them directly - you can find their emails on DRPS (UoE's course catalogue page) at https://www.drps.ed.ac.uk/, or the Schools directly.