You get this ending after beating 4/20 mode.
Listen out for Bonnie & Chicka(when any of em spawn near they make a quiet sound) when you hear them wait a bit and close the respected door, don't check your cams when any door is closed(cuz power duh).
When the doors are clear just open & close Foxys cam and pray she won't be too aggresive. When he leaves his cam close cams and wait. When you hear her running you have like 1-2 seconds to close the door. On my winning attempt he came 3 times so E.(but looks like she will change a bit in v0.0.8 and some things will change)
And one last thing Freddie, she will try to kill u once sometime past 5AM. All you need to do is guess when she will come in and close her door. I usually just wait for 20 sec after 5AM and close her door. When she laugth open the door she won't bother you again.(once again this will change a bit in v0.0.8)
Good luck, you'll need it)