Log on to the Admin Portal and navigate to the Phones Tab.
Select the intended phone and then go to Phone Properties.
Here you'll see a section called New Template. This is where you can modify the phone template to adjust lines/speed dials. Note that if you add more speed dials than your phone can display then you'll need to access the speed dial option on your phone to access them.
Update the template to reflect the amount of lines, speed dials, and buttons on your phone and click "Save."
Add your speed dials by going to Speed Dials menu under the phone you've selected.
Add the required Speed dials by adding the 4 digit DN or 10 digit DID. (Note that you will need to add your Dial Out Prefix before the 10 digit number.)