I originally had a post on how to clean up WinSXS from 2014. However, I have come across a program that I have tested, and works very well.
The program is Patch Cleaner. This program scans your Installer folder to check if there are orphan files relating to programs or patches you may have removed from your computer. Any orphan files Patch Cleaner locates can be removed.
I have tested Patch Cleaner on Server 2012 and 2012 R2, including production terminal servers with 100 users. I have no had any issues thus far.
With Server 2012, running Patch Cleaner was removing on average 20GB+ on each server.
I would recommend checking this out if you are still stuck for space.