Procedure

The first, and probably worst part is removing the front exhaust section - take great care when doing this as an old and fragile pipe can easily be damaged (don't ask how I know ..). However you only need to remove the front two joins which have 3 nuts each on, they should come off OK but if you have the chance spray penetrating oil on them the night before so they have a good soak first. When these joins are both detached you should be able to lower the pipe away quite a lot, enough to remove the sump anyway. You may want to remove this exhaust section all together, though it is not necessary to do so.

Next is the sump, which is held on by a fair number of small bolts and 4 nuts. Once these are all removed you should be able to carefully prise the sump off. Make sure there's no dents in it, as they could be restricting the oil pickup. If you have an oil level sensor then this will be the next thing you need to remove and tie carefully out of the way, there's 2 bolts hold this on. Now this is what you should see -

This is the wrong way up of course, and the oil pickup hangs down .. take the oil strainer off, there's one O ring round the end of that. Take the rest of the bolts out of the oil baffle and remove that (the thin plate). Remove the main fixing bolts from the oil gallery and remove that - lots of oil will suddenly leak out. This now exposes the 4 identical O rings in the gallery itself which butt up against the main caps, the pipe from the end has 2 O rings on when you remove it from the angled piece - which itself has one behind where it joins the oil gallery. Clean it all (I did it in petrol), let it dry, replace the O rings (part numbers below) and re-assemble it all - carefully using the correct torque settings. Fit a new filter and refill the oil. That's it !

When I restarted mine it was nice and quiet afterwards, and after almost 2k miles I've not noticed any of the previous rattles when hot or cold. Fingers crossed it will extend the oil change interval and rid me of the dreaded tappet rattle for a while at least.

Parts