Step 1: be home alone with the lights off.
Step 2: drink two Scotch ales, minimum 8% abv
Step 3: lock the door.
Step 4: start the movie after 10pm
Step 5: ensure that the door is in fact locked
Step 6: spend the first act of the movie looking into the deeper meanings, symbolism and such.
Step 7: lose the ability to do so sometime during the second act and start freaking out at every jump scare.
Step 8: no seriously, did you lock the door?
Step 9: grit your teeth and tough it out because you are going to sit there and get all the way through this movie, damn it.
Step 10: watch every single trailer and clip you possibly can for Anchorman 2 in hopes of forgetting the last two hours of your life and actually getting some sleep.