Hello,
To change the brand logos follow the below steps:
1) From the dashboard hover over the “Products” option and then click on Attributes and you will see the Brand Option then click the “Configure Items” as in the screenshot:
https://jmp.sh/vt6MCfU
2: Now from the list of brands. You have to click on “Edit” one by one:
https://jmp.sh/GEpqSmI
3) From the brand detail page. Upload your brand picture and hit the Update button.
Screenshot: https://jmp.sh/r4erhSZ
Best Regards.