How can I delete my admin account on my MacBook?

My MacBook is owned by school, and they created an admin account that can only be accessed by the school's ICT office. They turned on Parental Controls on my account. My friend helped me to create another admin account that I can access, because I couldn't do many things that I needed, like installing the printer, etc. Now we have to hand in our laptops to be updated, so I would like to delete my new admin account and then turn on Parental Controls again on the basic account. Is that possible? I cannot access the school's admin account that will be left.