Haha, they have to take the telescope apart in the summer to clean the optics (primary and secondary mirrors) as well as do preventative maintenance on various systems. Takes about 4 weeks in total to take it apart, and either clean the mirrors or ship them to AZ, then the wait for other work to be completed, then reassembling the entire thing.
Whats funny though, is the box of "random parts" that we ALWAYS end up with every year at the end of shutdown. Its countless nuts/bolts, and sometimes other more unique parts as well.