I have it, too. If it is is an orange-red color, it is already oiled (the oil-free cotton media is more whitish, in color, without the oil). They come from the factory, pre-oiled. K&N also sells a kit: solvent to remove the old oil, and dirt, and either a squirt bottle of their oil, or an aerosol can with their oil. The filters are good for 50,000 miles, between cleanings. The filter media, is cotton, not paper. The oil allows free air flow, while being v-e-r-y sticky, to dust particles. Hence the oil, and the periodic cleanings, and re-oiling routine. The filter, by the way, is supposed to last 1 million miles, if cleaned, and re-oiled, every 50,000 miles.
The kits are commonly available at automotive supply stores. If they don't stock it, they can, at least, order it for you. If you purchase it online, you will have to pay S/H; if you order it through an auto store, they
might get it for you, without charging the S/H. By the way, re-jetting is
not necessary... If you want to, knock yourself out, but I never did, and my bike runs superbly, with stock jets. Cheers!
1979 CB750K (sold, 2012, but not forgotten)
1983 Kawasaki 440 LTD Belt Drive (sold, 2011)
1993 Kawasaki Voyager XII