These instructions were useful http://www.vintagewatercooleds.com/tech ... -technote/ ... I managed to take it out, clean it up, grease and reinstall without any major issues. As a little note for anyone following them, when it says remove the handle you have to remove the handle and the little gear bit too!
Using some long bits of welding wire I cleared the blockages from the gutters so it shouldn't fill up with water anymore. The sunroof lining was very dirty so I pulled this off too...

Going to get some material to recover this.