Go to your Account Settings and click Edit Appearance. Then click Edit Theme.
Underneath Custom Theme, click Edit HTML.
Copy and Paste Script
Paste the POWr script into the HTML file between the Head tags. Once you add the script, click Update and save.
New Text Post
Back inside the Tumblr editor, add a new Text Element.
Copy and Paste Shortcode
Paste the POWr shortcode into the text post, then save Expand the post, and you'll see your new Social Feed plugin. You can edit POWr Social Feed by clicking the POWr Settings Icon in the corner.
To edit your Social Feed on Tumblr:
Visit the live Tumblr web page and click the settings gear in the top right corner of your Social Feed Plugin.