Instructions on how to open

Keypad on Door:

-Open as of Season 5: This video/code was released on Day 3, August 16: On Tape 1972-73 (Blue Dot)
-Code: 72948531

This is part of a massive community effort all started off by activision with clues leading to this website:- https://pawntakespawn.com/tv
A good explination of this was made in a video by JackFrag :- Video

Inside you will find:-
Various clues were discovered among the miscellaneous files scattered around. One intriguing discovery was a half-built RC-XD car, a classic killstreak found in Treyarch’s Black Ops titles. After noting all of the codes within the shed as well as each of the former days’ new numbers, the day was crossed off.

I also Took Screenshots of what looks like Puzzles/Clues to a BIGGER puzzle, see below:-