From the handset:

On the handset:

1. Hit the "OK" button
2. Use the arrows to select the "Settings" icon (looks like a gear)
3. Go down to option 8 "System Settings" and hit "OK"
4. Go down to "Base Reset" and hit "OK"
5. Enter the pin: 0000
6. Hit "OK"
7. Select "Reset to factory"
8. Select "Yes" when it asks "Reset base to factory settings now?"
9. Wait for approximately 5 minutes while the base resets, then the handset should be useable again. It should say "Provision successful" on the screen briefly once done.

From the base itself:

1. Unplug the power supply.

2. Long press the Paging button, do not release.

3. Plug in the power supply, observe the LED indicator lights until they all light up.

4. Release the Paging button

5. Restart the base by unplugging it from the power source for 30 seconds and then plugging it back in.

The cordless base will be plugged into your internet router or switch.

The cordless base is not where the phone charges / usually sits. That is the charging cradle.