Enter your credentials. The default username and password are usually admin / admin .
If the update fails and you cannot access the interface, you can try entering Recovery Mode by holding the Reset button while switching the power on. Wireless N ADSL2+ WI-FI Router DSL-2750U - D-Link dlink dsl2750u v2 latest firmware update link
Click on the MAINTENANCE tab at the top, then select Firmware Update from the left-hand menu. Enter your credentials