Hi Martin,
Create a subject, right-click on it and import your file like any other file with the menus “Review raw file” or “Import MEG/EEG”.
At the bottom of the list of file formats in the dialog box you will an option “EyeLink eye tracker (*.edf)”.
If you are not familiar with these operations yet, I’d recommend you start by reading all the “Get started” tutorials:
http://neuroimage.usc.edu/brainstorm/Tutorials
Cheers,
Francois