Configure Your Network Settings Manually - D-Link DSM-750 User Manual

Section  - Configuration
Use your remote control number keypad, or select the numbers from the on
screen number pad, to enter your wired network's IP address.
Once you have entered your IP address, use your remote control to navigate
to the Next option and press OK.
Click Next
Use your remote control number keypad, or select the numbers from the on
screen number pad, to enter your wired network's Subnet mask.
Once you have entered your Subnet mask, use your remote control to navigate
to the Next option and press OK.
Click Next
D-Link DSM-750 User Manual

Configure Your Network Settings Manually