Hi Marco,
You can do a bit a manual alignment: right-click on the channel file > MRI registration > Edit.
Then read the tooltips for all the buttons in the toolbar to learn how to do translations/rotations/scaling.
When you’re done, click on the button “Project on scalp”, then Ok.
If would be easier if you have some transparency for the head surface. The head should be transparent by default, if it is not check the Brainstorm preferences and enable the OpenGL renderer.
Cheers,
Francois