Sure! Here's a step-by-step guide on how to edit a thumbnail on your YouTube channel
Sign in to YouTube Studio
Go to YouTube Studio and log in with your Google account
Select Your Video
From the dashboard, click on "Content" in the left-hand menu. This will show a list of all your uploaded videos
Choose the Video to Edit
Click on the thumbnail or title of the video you want to edit
Edit the Thumbnail
In the "Details" section, scroll down to find the thumbnail options. You can select a suggested thumbnail or upload a custom one by clicking "Upload thumbnail.
Upload Custom Thumbnail
Click on "Upload thumbnail" and select the image file from your computer. Make sure your thumbnail meets YouTube’s recommended size (1280x720 pixels)
Save Changes
After uploading, click "Save" in the top-right corner to apply the new thumbnail to your video
Check Your Thumbnail
Go back to your channel or the video link to make sure the new thumbnail appears correctly