Step 1: Log in to your admin section. It is available at https://your-ghost-blog.com/ghost. Step 2: In the Ghost Admin, go to Settings → Design & branding Step 3: Click Change theme. It will open a modal window. Ghost settings to change the theme Step 4: Click on the Upload theme button, and select the flux.zip file. Step 5: After the upload is complete, under Installed themes click Activate. Check the installed Ghost themes That’s it! Now you can start customizing your theme.