Exchange - Opening Public Folder Management Console (2010)

Login to Exchange Server

Open Exchange Management Console

Click On Toolbox (Tree Item)

Select Public Folder Management Console on the Toolbox window

Click on Default Public Folder
Note: It takes some time to synchronize content, depending on the server

Select the folder and go to properties -> Go to permissions (tab)

Add the user, define the permission level

Note: Please make sure the permission are defined at the item level