Quick question about the "*MUST READ* How to install The Sims 3 correctly" directions

Quick question about the "*MUST READ* How to install The Sims 3 correctly" directions (because I have trouble interpreting directions, sorry >.<)

This is probably a dumb question because I haven't found anyone asking about it but here goes. In the directions for installing JUST the base game, it says "9. When the Installation is completed, open the '# Crack' file in this .rar and Copy + Paste the 'TS3.exe' to 'Game Directory > Game > Bin' and REPLACE it by the existing one." I've read people saying that you do this before you add the extensions, after you add the extensions, or not at all, but the master post with the directions doesn't specify!! What should I do in order to make my installation go smoothly??

I'm new here, but I can't wait to be a part of this community!!

If you want only the base game, you copy that crack.
If you are installing EP or SP, you only need the crack from the newest one.
If you use the patch, you use only the crack from the fix.