Change the skid plate on the Husqvarna Automower 220AC / 230ACX
Here is a step by step guide of how to disassemble and replace the skid plate on the Husqvarna Automower 310,315 and 315X. The same principle applies to a wide range of other Automower models. 
A warped, cracked or damaged skid plate leads to noise and imbalance in the cutting system.

Changing the skid plate is a simple process and doesn't require any special tools. See below for step by step instructions.
At the bottom of the page there is a list of the spare parts needed for the job.

Tools used: Torx screwdriver T20.

Step 1: Turn your Automower over. Find the four screws that hold the cover and skid plate in place Unscrew them.	Step 2: Lift off the skid plate and the cover.
Step 3: Place the new skid plate on the bearing holder. Install a new foam gasket on top of the engine protector plate.	Step 4: Screw in the cover and skid plate with the three screws.

Make sure all the parts can rotate freely after you have finished. Then just use your lawnmower as usual.