If you need to remove a property from your property list, this can be easily done.
Simply click on 'Properties' and then search for the desired property. Click into that property and you will find an 'Actions' button at the top of the page, to the right hand side of the property address:
If you click on 'Actions' a drop down will appear and at the bottom of that drop down you will see 'Deactivate property'
Once you've selected this, the system will give you a disclaimer and ask if you're certain about deactivating (make sure you're sure before clicking 'Deactivate property'):
There's also a guide here on how to find and reactivate a deleted property.