Installation
Just unzip the “biblatex-dw.tds.zip” file into your $LOCALTEXMF directory. Then refresh your filename database. In MiKTeX, this is done in the “Settings” dialog, button “Refresh FNDB”, or from the command line with the command initexmf --refresh-fndb. For other LaTeX distributions, please see its documentation for details.
Here is some additional information from the UK TeX FAQ: