Replying to Pranks for my principal

Ok so thats the deal, we need real pranks to do to my schools principal. She has been the worst bitch ever to us and to the whole school she just fired one of the best teachers on the whole school and she is fucking up all of our tradition.
So next year is our senior year and we (as my friends and I) would like to show her that we dont like her and that we are not going to be part of her shit.
Im not fucking around with this, we do not like her so we need good pranks to do to her.

So now we need ideas from you guys, we need pranks that she would be able to tell that we did them but there is no way for her to prove it so there is no way to punish us.

Sorry for my english.

Sparknotes: We need pranks to do to my schools principal, because she is a real bitch.