Gently push the wires and receptacle into the box – don’t force it. If the receptacle won’t fit, carefully rearrange the wires until you can tuck them all safely in the box.
Which way to face the ground plug on a receptacle?
Whether to install a grounded outlet with the ground plug facing up (as shown in the photo above) or down is a matter of debate among electricians. Some feel that installing the ground plug up is safer (since the hot prongs on a plug will not be exposed if it pulls partly out of the receptacle) while others think down provides the most protection (since the plug will still be grounded if it pulls loose). Both ways are considered acceptable under building codes.
Once the new receptacle is in place, attach it to the electrical box using the two screws so the metal “ears” next to the screws on the top and bottom are flush with the wall.