Step 1. Please navigate mause on the logo then Right click on it and then click Open image in new tab.
Step 2. As you can see It's located in "images" folder and name is "logo.png" (images/logo.png). Now you need to go to your site cPanel for example here: http://www.yoursite.com:2082 login with your username and password to upload new one.
Step 3. Please find File Manager in your cPanel and go to your public_html folder
Step 4. Please check if logo.png file is really in "images" folder and enter that directory.
Step 5. Now let's start uploading. NOTE: You should be in "images" folder and then click Upload. Before choosing file, make sure you check option : Overwrite existing files, because we already have a file called logo.png. Then choose file in your computer and click on upload.
Step 6. It's done. Now go back to your homepage, refresh it and check your results.