Hi Scott, In this case it was the rear, but the same part is fitted to the front. From memory it costs around £20, if that, including the gasket. The easy way to check is to disengage the difflock, put the car into gear and listen while someone lets out the clutch, as noises underneath often come from a completely different place when listened to from outside.
Last time I replaced both rear half shafts and drive flanges in about three quarters of an hour on the car park at work before driving home. Most of this was taken up in attempting to persuade the circlips to go on using a wire coat hanger and a pair of mole grips. All you need is an11/16th Socket and a pair of circlip pliers, plus something to lever off the plastic cap on the end of the half shaft.
Once you've identified where the noise is coming from by listening and watching if the prop shaft is turning, undo the five bolts in the centre of the wheel and pull the flange out enough to grab the halfshaft. You can also remove the circlip and pull of the flange, but which ever way you do it make sure that the vehicle can't move and scribe a line, or mark with paint, the position of the flange relative to the hub.
If this sounds, difficult, it isn't! These things were built for bush mechanics to work on in the shade of a tree, not in a fully equipped workshop. I've never done the front one, but I would imagine the procedure is pretty much the same, although if it isn't I'm sure one of the regulars will put me right when they recover from ther post Christmas anaesthesia! Cheers, John