Anything that you've learnt from Bear Grylls (man vs wild)but you used it in a real urban environment (most likely whilst being drunk)
When you cant get in your mates house after a big night out so you make a nest out of branches on the driveway and make a fire from your mcdonalds bag.
THATS BEAR GRYLLIN-IT!
1. To camp or sleep rough.
2. To complete an action with minimal tools or technology, usually in a ham-fisted manner.
This expression comes from star of T.V. show 'Bear Grylls: Born Survivor' who frequently throws himself into dangerous wild situations in a bid to educate the naive urban populations. There is some controversy over whether he actually 'Grylls it' or lives the cushty life whilst off camera.