change drive path

I am moving video from an old array to a new one. The sql table (dbo.videofiles) for the video has a column simply called filename. It shows the file path to each file which is currently Z:\video\filename. I want to point the file path to X:\video\filename but, sql doesn't like the Z: or X:. without manually going through hundreds of thousands of rows, how do I tell sql to change Z: to X:? Thank you in advance