As an ESO PI, here you can retrieve online your raw data while they are still protected under their proprietary period. In addition to the raw science files, the corresponding data package will also contain raw and master calibrations, science data products and ancillary information (processing logs, excerpts from the relevant observing logs, etc.).
Once you have logged in using your User Portal credentials, you are presented with a pull down menu that lets you choose one of your active runs for which the PI Pack is available (for obvious privacy reasons, only your runs are displayed).

You can, then, specify a time interval in which the data were acquired and press the "Select" button on the right to run the query. Not entering any dates will return all the available data. Please note that, for the sake of clarity, only the raw science files will be shown in return, not the complete content of the package that can easily amount to several hundreds of files (raw and master calibrations, reduced science, ancillary files, etc.).

At this point you can refine the search by modifying the date selection, or press the "Request Files" button. You will receive an e-mail confirming that the request was successfully submitted and another one once the data are made available to you. This latter message will also contain detailed instructions on how to retrieve the package.
More on the service can be found in the FAQ section. Should you have further questions or comments, please follow this link.