Export subset of data for development environment
I've use the script in this post:
Updating multiple rows with random values from another table
https://social.msdn.microsoft.com/Forums/sqlserver/en-US/f58c3bf8-e6b7-4cf5-9466-7027164afdc0/updating-multiple-rows-with-random-values-from-another-table?forum=sqlgetstarted

Generate the random data (another table) first:
http://www.generatedata.com/