To allow you to exercise your data protection rights in a simple way we are providing a dedicated section on the Steam support page (the "Privacy Dashboard"). This gives you access to your Personal Data, allows you to rectify and delete it where necessary and to object to its use where you feel necessary. To access it, log into the Steam support page at http://help.steampowered.com and choose the menu items My Account -> Data Related to Your Steam Account. In most cases, you can access, manage, or delete Personal Data in the Privacy Dashboard, but you may also contact Valve with questions or requests via the contact processes described in sections 8 and 10 below. As a resident of the European Economic Area or United Kingdom you have the following rights in relation to your Personal Data:

6.1 Right of Access. You have the right to access your Personal Data that we hold about you, i.e.
How can I change my data? 
To access it, log into the Steam support page at http://help.steampowered.com and choose the menu items My Account -> Data Related to Your Steam Account.