It isn't painful for them, I just got done doing some stripping on Barkley, he curled up on the table and went to sleep
Just take a very small amount in between the thumb and forefinger of one hand and lift that tuft up and away from the coat. Sort of fan that bit out like a hand of cards. If the light is right, you will see the fuzzy bits sticking out, this is what you pluck till it's even with the guard hairs (the smoother ones on top) You can also pinch the skin up and hold a bit of skin and pluck with the other hand. You do the same for all parts of the body.
The key is to work tiny sections at a time, and work in a line or some type of pattern, a section of the dog at a time. Don't expect to finish the dog in one go, it will take about a week of working about an hour at a time.
Good luck!