In the end I have subcontracted this task to a professional.
The pins and bearings on either side came out without issue and the mechanic reckons the bearings are good enough to re-use - perhaps testimony to rigorously washing the bike after every trail ride and applying WD40 to certain parts.
The lower shock bolt has been a different matter and it had to be cut, ground and drilled in order to remove it, with the bolt head being the awkward part.
Question is: how to prevent it sticking again? Application of grease every service?