Normally, you don't need to worry about working offline with Simul. If you open a document and then lose your internet connection, you can save the document as normal and office will upload it the next time you're online.
This is done via the "Office Upload Centre" which comes bundled with Microsoft Word. In the following example, the document "Tutorial.docx" is pending upload:
There are times however, when it makes sense to download a copy to be manually uploaded at a later date. This could be to send a copy to a co-worker for a quick one-off review / change.
To download a document, select the appropriate document from the documents console.
Select the "Publish this version" options from the "More actions" menu near the "Open in Word" button:
The Word document will be downloaded as a regular file. Please refer to the uploading guide for details on uploading any changes.