Welcome to the Webflow community, it’s the right place to get the support you need.
What you want to achieve can be done using interactions.
Basically you will create a wrapper (Brand Link) with 2 logo images inside of it.
Set the wrapper to ‘Relative’
Create a combo class for your 2nd logo
Set both logo images to ‘Absolute’ - full
Set the 2nd logo (combo class) of display: none
In the interactions:
Create a ‘Hover In’ interaction that will hide the 1st logo and show the 2nd
Create a Hover Out’ interaction to do the opposite.
Let me know how you get on if not sure.