Replying to Hacked the school computers grade system

As you pretty much know, teachers keep a grade system on the computer, and usually a hard copy incase anyone fools with the grades. The school system uses the teachers grades and calculates GPAS an keeps entire records of each grade you get in a class on a site known as " LEECA".

Earlier this year, sometime in the beginning of May, one kid i know is very good with computers. He found a program on every computer, similar to Synchronized Eyes, that allows you to monitor what is going on on a certain computer. Only this program has a case sensitive password, and you need the computer's username(which is the name it is hooked up to in our schools system). Each username is on the background of the computers desktop, except on the teacher's computers.

Don't ask me how, but he took the schools files and transfered them to a storage device, took it home and somehow figured out the password. He then figured out each teacher has the username of their first initial-lastname-1.

I thought it was pretty sweet, and not only can you monitor what people are doing, you can move their mouse around, and edit their text, open programs, pretty much anything you can do with the computer you're sitting at, you can do to theres.
But then i logged onto my bio teachers computer, she was looking up some notes on frogs, nothing too exciting. But then i had an idea!

I logged onto my guidance counselors computer, one that keeps track of the system i mention earlier( LEECA) I followed her for almost a week, watching her log onto leeca, enter grades, missed school days, tardies, everything. I even saw my name in the school's list. It seems so simple to edit my grades, and I have all next year to think of a system on how i can test it out... but it's very risky, and maybe not worth it. But until you see how simple the system is--- for example

9th Grade
Art 1 B-
Chemistry B
Etc

So what to do...

Cliff Notes- friend hacked schools grade system. Can change grades with minimum risk of getting caught, from another computer in the school.