Here you can find the instructions on how to change the Logo.
Method 1. Theme Options
➤ Please follow these steps when setting up logo image.
Method 2. Standard
1. Open the Magento admin panel and select Content > Configuration in the side menu.
2. In the list of stores you need click edit at Global-Main Website. Also, you can click edit for a particular store view if you have them.
3. Select the “Header” tab, and upload your logo.
5. Click “Save Config” button.
✓ Remember to refresh the Magento cache.