Help me to Change Logo and Site Information

[manhdev]

As Title.
I am using tp-link 741ND v4.
I want to customize the logo image of our company. However, I do not know how to change. The problem is that I copy the image to the right without replacing the old logo.
I have used the image size by how much? format of the image (.sgv, .png)?
I know a little how to use WinCP to intervene in the file system.
Please help me!

[encro]

I'm guessing that this is embedded in the firmware.
To change the logo you will likely need to create a new Theme as a custom repository.