Okey this is not for wow but it is a damn nice guide,
Equipment list
One permanent marker
One retard teacher (Who uses a whiteboard)
Go into your classroom just before class starts and take all your teachers drywipe markers, hide them underneath his desk or under a book on his table.
Get one of your markers and set in on the center of the teachers desk
do not buy a marker which says PERMANANT in bold up the side, if your teacher has any brains they will figure this out, but a marker which looks most like the brand your school would use, mabey even the same brand but just permanent. When your teacher goes to write on the board they will will write on it with the permanent
Tell the teacher that they spelt something wrong, or ask them to write it larger as you cannot see it and they will go to rub it out to find it doesnt work
Voila, Tinjoi before deletion!!