Open the WebUI on the NodeGrid where the logo to  be changed on the login page.

Select "System" and then choose "Preferences" on the menu.

in the middle of the page where "Login Page Logo Image", select "Logo Image Selection".

A menu of options will shows up. Choose "Update logo image from local computer" and click on "Choose File" button.

A dialog window will open up to browse for the image file to be loaded into the NodeGrid switch.

Click "Open" after the file is selected. Click Save on the NodeGrid Web page.

The NodeGrid main login page will show the new image saved.