Here's an easy place where you'll find Spare Parts for Woodcraft products of all types. 

The best way to use this section is to search spare parts for your specific bike using the shop by bike feature.  You'll find options that are both Universal and Bike Specific.  After you select your bike, you can then use the filters on the left hand side to narrow your choices.  To make the list targeted for your motorcycle, select the "Bike Specific Parts" box under the Fitment section at the left.

Some sections, like rearset spare parts, have Exploded drawings for the more recent models to help you find what you need.  To access those, fill out your bike in the Shop By Bike section and then navigate using the main menu or the quick access button below to the "Rearset Spare Parts" section.  

Alternate Option - use the product page to find parts
You can also find spare parts for most SKU's by going to the main page for your product.  For example, if you need a new skid plate and a gasket for a Left Side Engine cover for a 2010 Kawasaki ZX10R, go to the 60-0165LB cover page and just below the main product photo you'll find a tab that says "Spare Parts" that will have what you need.