Does anyone happen to have the picture associated with this step :

"You also need to fill the bottom of the mount. This can be done by taping or plugging the hole shown in the picture and filling it up (from the middle) untill you seem in coming out of the other holes (on the sides) like this:"

I have a new "solid" mount I'll drill and check and if I need ti fill it I'd like to know more about what I need to do and make sure I get it right.