Remember that damaged engine mounting bolt that I had to replace, but that would have required dismantling the entire primary chaincase and all the wonders it contains? Well, I thought I'm buggered if I have to do that, and so, as I thought I would, I got creative.
Inspired by a surgical technique known as maxillary antrostomy (don't google it, it's super gross), I drilled an opening in the inner chaincase directly in line with the offending bolt, and was thus able to extract it, then replace it with a new one.
During the procedure, the engine was supported on a jack. Now, if only alluminium could heal itself like bone and tissue do...
Many thanks to Witold, who consulted on the procedure.