Visa option to select in ISD. from Stamp 1G to Stamp 2

I am going back to college and got my offer letter. I arrived in ireland back in 2022 for masters and then got a job. and now unhappy and unstatisfied with what i studied and want to change my industry to which i have. My stamp 1g expires in Nov 2025. and my college starts in sept 2025. what is the process like which option should i choosing on ISD to apply for Stamp 2. i know its quite early but i prefer to have a game plan before actually paying my fees and applying for stamp 2. any help is appreciated.