What is the answer in plain terms?
Multiply your goal weight in pounds by 0.8 and by 1.2. That is your daily range in grams. If you are aiming for 180 pounds, it is 144 to 216 grams. Most men do well in the lower half.
How do I spread it out?
Split it over three or four meals. For a 180 pound goal, that is about 32 grams at each of four meals.
What if I miss it some days?
Nothing breaks. Look at the week, not the day. Two or three days a week on target, with lifting, still moves you forward.