Replacement through shaft and bearing carrier. The shaft, endplates and spacer are made from stainless steel.

Shaft assembly comes delivered with the bearing carrier in place; remove your original shaft and endplates, slide the new complete shaft into the outer hole nearest the wheel arch, there should be just enough to swing in around and slide in, push in until the new bearing carrier pushes up against the hole, then line carrier up so you can drill the two 5mm holes, drill the holes then bolt up the bearing carrier with the shaft in place.

Then the other end of the shaft you can slide on the stainless steel spacer, bolt on the endplate with the spring hole towards the engine, making sure to line plate up with the two flats on the shaft, tighten Nyloc nut up then hook up the spring as in the image. Thats the new shaft fitted, if you find shaft doesn't rotate freely this can be because the area where the bearing plate is bolted is not square to the chassis, you can tweak this area with adjustable wrench, after 40 odd years of abuse those plates take a pounding.

This shaft can be fitted from the wheel arch end, originally VW fitted these before fitting the brake master cylinder, so to replace from the inside of the chassis you would need to drop the master cylinder. But with this there is no need to .

One of the tips I have been given is its easier to hook the throttle cable to the endplate before bolting onto the shaft as there is not much room up in there.