I have cut and pasted this from a previous post from last year.
Hope it helps
I used gf book too. Again, just the gist of it.
Both you and your dc have to be 'ready' and have a clear week, I'd say. i.e. not when you about to/just had baby, moving house, either of you is poorly, when your mum is telling you to do it .
Start by getting them to sit on the potty every 20min or so and read a book. They get a choc button for that (and two for mummy). Once they have the idea of sitting on potty when you ask them to, you tell them that they will have a choc button next when they do a wee/poo on the potty. Lots of clapping, praise, phoning daddy when they do.
THEN, start asking them if need to sit on potty. Only sit on potty when they say. i.e. 'do you need a wee?'. Choc button, claps, etc when they perform.
THEN, tell them they need to tell you when they need a wee. 'don't forget to tell me when you need a wee'. Choc button, claps, praise, etc when they have told you they want to go.
Don't worry about accidents, just re-iterate that they need to wee on potty. Keep potty in same room as you and dc, move it around with you. Then once completed all above steps, move potty further away from where you and dc are, towards loo so that gradually have to hold on for longer.
Potty traing a success once your dc can TELL you when they need to go and hold on till get there.
Another tip, use trousers and pants that are slightly too big as easier for them to pull up and down and t-shirts that are too small as don't need lifting up.
Job done