1. Open Outlook
2. Go to File ---> Import and Export (Open for Outlook 2010) ---> Import from another program or file ---> Outlook Data file ---> Browse your PST file and select do not import duplicates ---> Click on your name/data file (root folder, as shown in the image below, or any folder in the PST file that you wish to import) and check Include subfolders. Also select the new mailbox to which you want to import from the dropdown under "Import items into the same folder in:" ---> Click Finish.
If you want to import the entire profile, click on the "Outlook Data File". If you want to import just specific folders, like calendars or contacts, then select that folder and click Finish.