This is how my doctor instructed me to wean off caffeine......

Start the week with removing just one serving of caffeine from your regular drinking schedule, continue each preceding week with removing a 2nd serving, then a 3rd and a 4th, with each week that passes, until you are finally down to no caffeine what so ever.

If you are weaning off of coffee try substituting the removed caffeine drink with decaffeinated coffee or hot tea.