First off, go to portal in your steam library, right click on portal, click on properties, then click on the section named "local files" and click on "Browse Local Files".

now you may see your in portal's game files, that's good, now we are going to the direction hint file!

go to the folder named "portal" without capitalization, then find the folder named "resource" thats where the direction file is!

you're in the resource folder, thats good, but you may see alot of text files, the file we are looking for is named "portal_english" or what ever language you speak,
now, just click on the "portal_english" file, once you are there, you basically have the direction hints in that text file. and im not good at explaining things, so i cant really explain what equals what.
well i hope you found this guide helpful, or not, i dont know