How do i mount a scope to a Mossberg model 42m 22?

Go here: <http://www.havlinsales.com/> Click on .22 parts & scroll down 1/4 of the page for MOSSBERG .22 SCOPE MOUNT For models 26B, 26C, 42A, 42B, 42C, 42M, 43, 44US, 46A, 46B and 46M.