They literally just pull out and swap out. The two snorkels are the same size for the opening. The original will peel out if you try hard enough. They are a tight fit both coming out and going in.

Now I will venture to say most probably just pull the lid or at least the snorkel and leave it. I figure there is a chance some time that I may encounter a situtation where water washing over the top of the box may be an issue, so I stick with the snorkel. I did measure the cross sectional area of the snorkels. The KDX snorkel is virtually the same size as the air box to carb manifold tube, where the stock one is around half that..

 

Snorkel pulls out the top, as stated push lip in on bottom and wriggle that sucker out. When installing the KDX 200 snorkel install from top in, a little grease around the lip goes a long way in helping it snap in.