If it's hit a stable FG, you can cold crash now. I routinely cold crash beers after 10 days in the fermenter.
To cold crash, just put it in a 40 degree fridge (you can go colder -- even 32 degrees won't freeze beer due to the alcohol content). If you don't have a fridge and are using the "water bath with frozen bottles" technique for temp control, feel free to just drop in a LOT more frozen bottles to get it nice and cold. Let sit a few days at that temp and most things will drop out of suspension. Then you can package it up.
Just ONE thing to be aware of -- the changing pressure in the fermenter due to temperature gradient will try to draw in air through your airlock/blowoff. This is a possible oxidation/infection concern, but a VERY minor one. An airlock is fine, but if you're using a blowoff tube, it might suck the blowoff vessel liquid back into the fermenter. Not good. So be aware of and watch this to ensure you're not sucking anything but air into the fermenter with the pressure change.
