Part time to Per Diem Employee?

I have two CNA jobs--one is per diem, the other is part time. The per diem one is a job that I love more. At the same time, I am also a senior BS Nursing student. I have just started both jobs just a month ago. I realized that it was hard keeping up both the school and work, but I needed the money to pay for school. Now my question though is: Would it be alright for my manager in my part time job to tell her to change me to a per diem employee instead, so ill have more time for my school? Or is this even possible? I want to keep both jobs and I dont think it is alright to resign with the part time job because I just started a month ago. Thank you guys for your input!