Mark a 3mm drill bit at 8.5mm from the tip. This will be the depth of
the two holes you will need to drill. When finished, the pins should sit
flush with the surface of the wiper arm bracket. Before drilling be sure
to block the airbox to prevent any metal shaving from falling in. A ragged
stuffed into the opening works just fine.
Please note, some versions of these steering dampers may use only one
pin to secure the steering nut bracket.