First of all Rob i dont know how you got the retaining clip out with the cv joint still in situe but seeing as you have there's nothing to stop the joint from coming off the shaft,as i said before it's just a case of persueding it with a heavy hammer,if you make sure the cv joint is straight like in the first picture when you hit it it will come off,it's obviously being stuborn like most female's but persistance will pay off

p.s if the hammer in the second picture is the one your using you will have trouble,get yourself a club hammer,you need to use something with a bit of wieght to it.