Very simple, very easy. I line a clean, plastic 5-gallon pail (from HD or Ace Hardware, etc.) with a food grade turkey bag (and rinse and use it for roasting the turkey). It helps to "get personal" with the turkey and use fingers to loosen the skin from the breast and legs without completely separating the skin from the middle of the breast. Just enough to allow the brine to penetrate between the skin and meat, as much as possible.
Brined & Roasted Lemon Thyme Turkey
1 cup table salt
6 lemons, zest and juice (discard rinds)
1-2 tablespoon(s) dried thyme according to taste (use 1 T the first time)
2 gallon ice cold water, divided
1 12-14 lb. turkey, rinsed and thoroughly dried with paper towel
5 large onions, sliced
Disposable roasting pan
The day before you brine the turkey, combine salt, 1 gallon water, lemon zest, and thyme in very large stockpot and bring to boil. Cool to room temperature, add lemon juice then place in refrigerator to cool completely.
In a very large plastic bucket (at least 5-gallon), combine brine and 1 gallon ice water. Place turkey in brine breast side down and completely submerge. Place container in refrigerator or cool place that is below 40 F. Brine at least 6 hours , and no more than 24 hours, flipping turkey once.
Remove turkey from brine, rinse very well and dry thoroughly. Discard the brine.
Adjust oven rack to lowest position and heat oven 400F. (Optional: place turkey in roasting bag, and close using a method that allows easy access to turn the turkey. Less cooking time will be needed using the bag). Roast turkey on a rack in a large baking pan lined with onions (keep some water in the bottom of the pan at all times, so onions do not burn), breast side down, 45 minutes. Remove pan from oven and close the oven door. Turn turkey on its side so that one leg/thigh faces up. Return turkey to oven and roast 20 minutes.
Remove turkey from oven again. Turn turkey on its other side so that one leg/thigh faces up; roast another 20 minutes. Remove turkey from oven for final time and turn it breast side up; roast until breast registers 160-165F, and thigh registers 170-175F on instant-read thermometer, 30-45 minutes.
Transfer turkey to platter and let rest 30 minutes before carving. Reserve pan juices to make gravy.