how do I show hidden files?

Choose Utilities from the Finder’s Go menu, open the Script Editor, and run the following:

tell application "Finder" to quit

do shell script "defaults write com.apple.finder AppleShowAllFiles 1"

tell application "Finder" to run

(227543)

Try the key combination ⌘ ⇧ .

(Command Shift Period)

It toggles between hiding and not hiding files with the "hidden" attribute.

Might not work on all Macs; I don't know.