(adsbygoogle = window.adsbygoogle || []).push({}); 1. Go get enough beer to get sh*t faced from one of Los Santos lovely corner stores.
2. Drink all 10 beers and as your are drinking the last one have a friend shoot you.
3. As you die go into passive mode.

Not sure if the last step matters but it gives you the vision of being drunk not the physical effect of like falling and stuff. To get rid of it just die again your use to it (its gta)