Half-Life 2/Our Benefactors

Name 1
Once you arrive in the tunnel, keep on going forward. There, you'll see the lower outside of the Citadel. Follow the path of rocks on the left, until you'll see a metal "log". Jump from it on the platform ahead. You'll notice that it's regularly moving. Once it's up, go left. There'll be a smooth path, also on the left. After some time you'll appear in a room. Go to the other end, then left and as path goes (this will include a few small falls, but none of those will hurt you). You'll see a room with capsules moving both ways. If you'll pick to go left, you'll certainly and simply die. Thus you should pick the right way - just jump in and wait.

Name 2
First of all, keep on waiting. You'll be doing that a lot at the beginning. Once you'll arrive at your destination, you'll drop out of there.

Name 3
You'll start by losing all your weapons, except for the Gravity Gun. This will become organic. Keep on going, killing everything in sight, until you'll see a loading screen. There isn't much else.