It is HIGHLY suggest to read my Wiimote in Windows tutorial before attempting to follow along with this tutorial.
Section 1: Ready GlovePIE

It is assumed in this tutorial that PPJoy and GlovePIE are properly installed and working. So, the first step is to grab my script which was designed just for x360ce.

- WiiCC x360ce Mapping Script v1.0 - Download

Contact me at:

  x360ce + Wii Classic
Controller Setup Guide
Load the script in GlovePIE, and click "Run" to fire it up.
Section 2: Installing x360ce

Installation is simple. Copy x360ce.exe to the base directory of the game you wish to enable controls for.

In this example, I am installing it for the game Bastion (Good Old Games version).
Section 3: Configuring x360ce

By default using my script, almost all buttons should be ready.

Load up x360ce, two prompts will appear to create x360ce.ini and xinput1_3.dll. Yes to both.
Now it wants a settings file, but we're gonna go with the defaults (Search automatically for settings).
Guide and D-Pad will be missing, but they can easily be added with the dropdown menu.
Hop on over to the PPJoy Virtual Joystick 1 tab, and note the "IG" identifier. Press Save when you are done, and you can safely close x360ce.
Section 4: Configuring the x360ce.ini

We're almost done! But, there is one last step....

Edit x360ce.ini with a text editor (I prefer Notepad++), and look for the [Mappings] header. Here you will need the IG identifer as PAD1, but it will most likely be PAD2.
This is because Windows sees the wiimote itself (Nintendo RVL-CNT-01*) as the first controller, but it is not actually configurable and therefore unusable without PPJoy.
When it's done, save the x360ce.ini file and you should be ready to go. Load up the game, and it should now see the Classic Controller as an Xbox 360 Controller!