how long will it take to complete a certificate in performance?

two years ago i finished all the ameb levels from preliminary to 8 but i took a break since i was entering my highschool exams. i’ve always known i wanted to come back and now that i’ve gotten into uni i want to do everything i had to postpone. obviously i know it won’t be easy but i’d like feedback from people who’ve completed higher ameb or the equivalent. for those who don’t do ameb, the cert of performance requires a 45 (?) minute performance and comprehensive knowledge of the text, i think it’s equivalent to dipabrsm, tcl advanced cert and diplcm (don’t quote me on this please.)

the thing is, i’m also a full time engineering student, who works as a tutor on the side so i’m definitely not going to be able to practice as much. i was thinking of doing lessons fortnightly. but with this set up, how long do you think it will take / how hard should i expect it to be? any advice or feedback would be greatly appreciated!