so i discovered that you can glitch into the wall as shown here: http://imgur.com/a/IE5OB

How to do: if there is a wall next to the stairs and you are able to drop down move to the right or the left (depending which side the wall is) for 2-3 steps and you should be able to clip trough

Note: does not work with all stairs

Just found out how to get out of the map will make a video explaining these

Here's how it works: