How to customize an existing permission level in SharePoint 2010

 ·         Verify that you have one of the following administrative credentials:

o   You are a member of the Administrators group for the site collection.

o   You are a member of the Owners group for the site.

o   You have the Manage Permissions permission.

·         On the Site Settings page, under Users and Permissions, click Site permissions.

·         In the Manage section of the ribbon, click Permission Levels.

·         In the list of permission levels, click the name of the permission level you want to customize.

·         In the list of permissions, select or clear the check boxes to add permissions to or remove permissions from the permission level.

·         Click Submit.

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