Log in Galaxy/Cistrome. Then click User -> Preferences in the Navigation Toolbar
In the new dialog, click ManageOpenIDs
Make sure you have already logged in GenomeSpace
Select GenomeSpace in the Combo box of AssociatemoreOpenIDs section. Then click Login button in the bottom.
Congratulations! Your Galaxy/Cistrome account is linked to the OpenID of GenomeSpace now and you can use everything GenomeSpace provides for Galaxy/Cistrome now.
To export data to GenomeSpace is also easy. Click ImportData -> GenomeSpaceExporter, select your data to send and Target Directory, then click Excecute.