If you put your capacity at "0", you will not be auto assigned any orders and UWM will see that you do not want any more at this time.
To do this, click on your name in the top right corner and click Users (may appear as "My Profile" depending on your user role).
Click on your name and then set your assignment capacity in the details section:
Now you won't be included in the auto assignments for UWM Appraisal Direct orders. You can change your capacity settings anytime.