The Wixel shield ships with all of the surface-mount parts populated. However, soldering is required for assembly of the included through-hole parts. The following through-hole parts are included with the Wixel shield:
The left picture below shows a fully-assembled Wixel shield, and the right picture below shows that assembled shield being used with a Wixel and an Arduino Uno. Note that the header pins should be soldered into the rows of through-holes as shown in the pictures below; the inner rows provide additional access to the Arduino and Wixel pins.
Note: If the headers are not soldered in straight, it might be difficult to plug the shield into the Arduino or the Wixel into the shield. One technique for soldering headers on straight is to solder only a single header pin to the shield. If the header is not straight, you can melt the solder on this pin with your soldering iron and adjust the header with your free hand until it is. You should only solder the rest of the header pins when you are sure the header is straight.
If none of your Wixels has header pins soldered in, you will need to assemble at least one Wixel with the included male headers as shown in the picture below:
Once the male header pins are installed, the Wixel can be plugged into the female socket on the Wixel shield. You can skip this step if you purchased a fully-assembled version of the Wixel.