In 2002, the McMath telescope mirrors were recoated. To recoat the mirrors, the mirrors first must be removed, then transported to one of the companies that can handle mirrors this size, then transported back and reinstalled. Due to the size (and weight) of the McMath telescope, this is an involved process. In 2005 and in 2010/2011 this process was repeated.
The following links show photographs taken during these operations (except that we don’t have photographs of the 2002 mirror reinstall). There also was a tree trimming work party that took place on the same afternoon as the second mirror removal and there are photos of that as well.