How to Convert a Feed-Based Page Layout to a Standard Page Layout in Salesforce

Because a feed-based layout cannot be directly converted to a non-feed-based layout after creation, the recommended workaround is to create a new layout cloned from the existing feed-based layout, with the Feed-Based checkbox left unchecked.
Once created, a page layout with the Feed-Based Layout checkbox enabled can no longer be changed to a non-feed-based layout. To convert the feed-based layout to a regular page layout, use these steps as a workaround:

1. From Setup, click Customize, select the object, and click Page Layouts.
2. Click New.
3. Choose the existing feed-based layout, which is cloned as the starting point.
4. Type a name for the new layout.
5. Leave the Feed-Based checkbox unchecked.
6. Click Save.
7. Click Save again if there are no other necessary changes in the page layout.

After this, click Page Layout Assignment to assign the new page layout to the appropriate profiles and record types.