Hahaha funny question 
1 tell the boy to get a book from the shelf 
2 tll the boy to go far away from the librarians site
3 let him sit with his frends in a group
4 and let him be hidden in between 
5 tell him to get the page to tear and tell him to tear it off 
6 to avoid the noise being heard tll the freinds to make some noise  or do something mad 
7 make sure there is no mark on the book that shows like somebody tore a page from the book 
8 return th book happily back and go away of the library and dont tell chaplas who can report to the mam 

haha tried it once dats ma experience