half shaft worn

So the front left half shaft on my 200 tdi 92 reg has rounded at the wheel end so that the half shaft will just spin inside of the drive flange, i think that the teeth have snapped or something. anyway i am going about replacing it but i am confused at whether the cv is also replaced or not or if (just the end bit after the cv joint can be replaced) and whether the cv joint will have to come off at all. i hope that i make sense and have had a look at busters guide on cv replacement.

Oli

cv just knocks off half shaft .will need to hold spring clip in with 2 screw drivers while refitting new one

so if i understand properly the whole half shaft is two separate pieces, one at the diff end and the other at the hub end, they are separated at the cv joint and you are talking about the hub end? and i no not have to remove the cv joint to replace it?

if drive memebers worn cv usually is ,cv is seperate to half shaft ,and would need stub axle off to remove cv