The needed Google Email configuration can be performed via cPanel for your account -> Mail -> MX Entry. There are few easy steps you need to accomplish here. First choose the desired domain name from the drop down menu.

By default the Mail Routing is set to Local Mail Exchange.

You should change it  to Automatically Detect Configuration. This will ensure the MX records you are about to setup are used.

Under Add New Record consecutively add the records provided by Google.

You will have to enter all records provided to you by Google following the priority specified by them and the destination. All will be automatically assigned for the domain name you have chosen from the drop-down menu.

Finally you will have to remove the default MX record added for your domain name. If no changes were previously made it is the one with priority 0 pointing to your domain name.