I have unclaimed T2202A (university credits) forms from 2015, 2016, and 2017. How do I properly add them and my 2018 T2202A to be claimed for my 2018 Tax Return.

I'm looking to use my unclaimed university credits from previous years in order to maximize my return so that I can start some investments. I want to properly claim them with the correct forms, how do I do so ?