How to request access to someone elses calendar in Outlook 2010?

Software | Microsoft Office

Open Outlook 2010.

Go to the Calendar overview.

Click on “Share Calendar”.

Type in the colleagues of who you want to request access to their Calendar .
(Or click to and select the according user names in the pop-up and click OK)

Check “Request permission to view recipient’s Calendar” to request access.

Check “Allow recipient to view your Calendar” to share your calendar with the selected users.

Click on "Send".

Wait until you receive a message back from your colleague granting (or denying) access.