GZip existing varbinary(max) column in Sql Server 2008+

I have an existing legacy table that is ~180GB in size due to a client application storing PDF files as varbinary. I'd like to be able to compress that column for all rows using GZIP to help save space while I create a new solution (I was hoping there was a way to do it in SQL and not have to write client code for this). I see that the COMPRESS method is available for Sql Server 2016 but I need a solution that will work with 2008. Any ideas would be appreciated.