Remove old version:
rm ~/Library/InputManagers/Edit\ in\ TextMate
Create InputManagers folder:
sudo mkdir /Library/InputManagers
Copy the input manager to /Library:
sudo cp -pR /Applications/TextMate.app/Contents/Resources/Edit\ in\ TextMate/
Library/InputManagers
Ensure everything is owned by root:
sudo chown -R root:admin /Library/InputManagers