Registered Forum User
Ducati Corse
Posts: 3,134
Join Date: Jan 2002
Location: notts
Mood: Bloo and Yellow.. and Red now ;)
The holes are offset to line up with the bellmouths. There's usually a "front" marking on the filter to, as the leading edge isn't as thick as the rear.
Put your hand inside the filter, thru the rear whole and work the front hole over the bellmouth from inside. As you pull your hand out, fit the rear over the second bell mouth.