Sticker has been ordered what would you class as high mileage
because that looks quite awkward haha, got a pal that could probs do it for me though!!
If it's over 50k, it's probably worth doing. If it's over 75k, is definitely worth doing. Will cost you approx. £13 + postage for a couple of gaskets, and about an hour of your time.
If karlos76 & I can do it, then anyone can !
Car will thank you for it, with a smoother and more responsive drive.
The "How to" link that I posted is dead easy to follow.