Open the Script Editor or AppleScript Editor in one of the subfolders of Applications and run the following:
tell application "Finder" to quit
if (do shell script "defaults read com.apple.finder AppleShowAllFiles") is "1" then
do shell script "defaults write com.apple.finder AppleShowAllFiles 0"
do shell script "defaults write com.apple.finder AppleShowAllFiles 1"
tell application "Finder" to run
If you change your mind later, run the script again.
There's a terminal command to do it, but maybe this would work better...
Do like said above, but then after entering the library, press cmd and 3. That will make the folder viewable, temporarily. Then, drag it to the sidebar of finder for quick access.
If that isn't good enough...
defaults write com.apple.finder AppleShowAllFiles TRUE