Had to do mine when I first got the car. Make sure they get you the o- rings and the blanking bit thats associated with it. Might as well change whole lot.
037 121 132 E - flange
357 121 140 - plug
+ N 903 168 02 - seal
032 121 142 - retaining clip
+ 037 121 687 - seal
N 902 809 04 - bolts
That lots off wagenstad, I'm sure someone will correct me if I'm wrong. Otherwise I'll check my invoice when I get home.
Its two bolts and a load of hoseclips Shady, I think even you could manage this one

edit: I just checked my invoice, and its all there. Shouldn't come to too much. I changed both my flanges and all the bolts washers etc when I did it and inc VAT its less than £40