How to clean Xcode and Simulator's cache?

Please first close Xcode and all simulators.

Open Finder, press ⌘+shift+G, then enter the file route respectively:

~/Library/Developer/Xcode

You may clean all files in these 3 folder:

~/Library/Developer/CoreSimulator

You may clean all files in this folder:

You may empty the rubbish bin and restart Mac.

Reference:

deskside / emodiary