It already comes with the
hl2/media/directory, so just extract here; making sure to replace
Steam/steamapps/common/Half-Life 2 Deathmatch/
Steam/steamapps/common/Team Fortress 2/
Special instructions for Portal 2 and Left 4 Dead 2 are on the download page.
I noticed there are a few of these on GameBanana already meant to replace the Valve intro, but this one is a new rip at native resolution and doesn't have any kind of DivX logo or other watermarks.