Depends on the platform. If its an MCS platform, just plug in a USB keyboard and mouse and a monitor. User credentials will those configured for the platform (e.g administrator) and password. The GUI credentials won't work.
Thanks for sharing this. I have a small query.
Keyboard and mouse can be connected through the USB port , how do one connected monitor.
Also, do we need any kind of terminal emulator , like the one used to console login a switch.
Mine are MCS 7845-H2 and have a standard 15 pin D type VGA connector to the left of the USB ports on the front.
You might find that if you have a different model, the VGA connector is on the back. I use just a standard LCD type monitor, no terminal emulation is required.