1. Just play the game a few times and the new content will naturally come to you.
   
2. If you feel you're fresh out of directions, pay attention to the surroundings for anything new.
   
3. When the meeting room changes, the whiteboard in front of you is a checklist (you'll need to be empty-handed for item 4).
   
4. After you complete the checklist, the same whiteboard will give you one further hint. (If, for some reason, you don't see it, it says "REBOOT THE GAME ENTIRELY.")

Simply play the game from the start to an ending a few times. Approximately 3 runs are required if you answered "Yes" when asked "Have you played The Stanley Parable before" at first-time setup; more if you answered "No".

Note: Some new content is already available at this point.

Now, before reaching the two-door room, you will see a half-open "new content" door. Go in, and follow the linear path to the end.

Note: Jumping in the Jump Circle is optional. In fact, the remaining jumps are carried over to future appearances of the Jump Circle, so if you spend them all now you will not be able to jump later.

Now, the Narrator will ask you to go into a vent. Be sus and go in, and follow the linear path until you are in a room with a skip button. Press the button a number of times. It's your choice how long to wait before pressing the button; each time the narration will eventually loop or stop. Eventually the Narrator won't talk anymore, and the room will start decaying during skips. When the button has fallen to the ground, turn around and walk out of the room. The game will restart soon after.

Now, the "new content" door will have a neon sign saying "new new content" pointing towards it. Go in and follow the linear path to the expo. Make sure to grab the collectible before you leave; visiting the other exhibits is optional. For the exit, turn right in front of the map, which is opposite the "collectibles" area. Then, simply watch until the restart.

Note: After this point, the bucket will be available to you, and with that much of this game's new content. But that's not all, so keep going.

Now you must collect all 6 figurines (including the one from the expo). Once you get your second, the meeting room will show hints for where they are, with the ones already collected crossed out. The hints, and where to find the corresponding figurines, are as follows:

1. Inside of a sequel exhibit. You should have already picked it up from the expo. If not, then go back through the "new content" door a couple of times to get back to the expo and pick up the figurine.
   
2. A large room. Lots of boxes? Go to the cargo room (right door -> straight), go up the ramp onto a box, and then jump down onto the wooden walkway on the left and follow it.
   
3. Stairs... something to do with stairs. After the meeting room (left door), go down the stairs and look under the staircase.
   
4. Somewhere both RED and BLUE In the cargo room (right door -> straight), take the cargo lift, then jump down onto the catwalk. In the red and blue doors room, look to your right. Do not bring the bucket with you or you'll not be able to get this one.
   
5. Nearby a fireplace Go to the boss's office (left door -> up), open the secret passage with the keypad, then in the secret passage, look to the right, opposite from the elevator.
   
6. A private (but smelly) place for an important person From the top of the staircase (left door -> up), turn left and go into the Executive Bathroom (click on the door to open).

At the next restart, the Narrator will interrupt your path. Follow the new, linear path to the end (when there's a fork, pick whichever way you like (the left path is always the right answer)).

Note: Collecting the figurines along the way is optional.

If, at this point, the "Epilogue" option is not available from the title screen, then close and relaunch the game a few times, following the setup prompts until the title screen each time, until the setup screen says "it's time for me to leave". Play the epilogue. Wait around until a broken arch and a building in the distance appear, and then enter that building. Follow the linear path to the end (collecting the figurines past the second underground area is optional). At the very end, there is a cubicle with a computer. Go in front of the computer. Agree with the setup screen's proposal (if you don't, then you have to replay the epilogue back to this point and agree before you can proceed) and proceed to the end.

Go into the "new content" door a couple times until you make it back to the expo. Go to the "free achievement" exhibit and use the machine.

From this point, the style of the menus and the title of the game depend on whether you completed the expo ending last or the epilogue ending last. To switch to the other style, just play the corresponding ending. You'll be asked to make a subtitle each time you launch the game either way.