Kelvin I looked at your current logo and it is stored in styles/resurgent/xenforo/themesinc_misc/logo.png
You can store it there, and you'll need to change the image path in Style Properties to the name of your image.
If your image is already named logo.png, however, you could store it in that xenforo folder so that it is outside of the themesinc_misc. That way, the logo won't get overwritten when the theme is updated.
How do I replace the XenForo header logo with my own?
Upload your logo to the server and change the image path in the ACP -> Styles -> Style Properties -> Header and Navigation -> Settings: Header Logo Image Path.