Don't know if they supply the filter with any filter oil, but it's worth oiling the filter before fitting.
I use PJ1 filter oil on mine. Very messy, but worth doing so all the dust gets caught.
Remove the rubber bungs.......and the original filters to
I find fitting the thing easiest if you put your hand inside the rearmost hole and work the front hole over the bellmouth from the inside. Fitting the rear is easy enough from the outside of the filter.