Here we start Removing form components.You can remove tabs, sections, fields, relationships, sub-grids, iFrames, and web resources from a form.
Follow these steps to remove a form component:
1. In the navigation pane, click on Settings.
2. In the Customization group, click on Customizations and then click on Customize the System to open the default solution.
3. Expand the Entities component and then expand the entity that you want to customize.
4. Click on the Forms sub-component and open the form that you want to customize.
5. Select the form component that you want to remove.
6. In the form ribbon, click on the Remove button.
7. In the form ribbon, click on Save to save your changes.
8. Click on Publish to publish your changes.

Warning—removing components
Removing a tab removes all the sections contained within the tab. Removing a section removes all the fields contained within the section. Some relationships—such as the activities and closed activities relationships—cannot be easily added back to the navigation area.