TWR basics are very easy to learn and use.

1. Check for level of pain at the start, on a scale of 0 = no pain to 10 = the worst it could be

2. Alternate tapping anywhere on the left and right sides of your body 

3. Focus your awareness on how you feel about the problem, stating it out loud if possible, or silently to yourself if that’s better for you
e.g. Even though I feel this pain, which is at a level 8
And I’m terribly frustrated by how long I’ve had it and how it has seriously limited my abilities to _____
And etc. etc.

4. State a counteracting affirmation
e.g. Nevertheless, I still love and accept myself, wholly and completely
Or
I remember when I was free of pain and know I can be free of pain again
Or
I remember when I felt pain-free and whole and happy
Or
I remember being on holiday, totally care-free and enjoying myself
Or 
Whatever positive statement or affirmation feels strongly positive to you

5. Stop tapping and check again how strong your symptoms are

6. Continue with further rounds of tapping, as above, till the pain is down to 0 if possible. 1 is also acceptable.
Your pain may decrease in little steps or in great leaps.

7. Writing down what you say is extremely helpful. If it works with the words you used, you’ll then have them to use again. If it doesn’t work at all or if you’d like it to work better, you can tweak or change the statements you use as you tap.