I’ve worked for a company while it was applying for Cat III ops qualification. We had to log x number of simulated Cat III approaches, in Cat I or better weather, down to an auto-land and write a Cat III report for each one of them. These reports, together with the training documentation for each crew member’s low-vis training and various maintenance documentation was then finally submitted to the authorities for final approval. Its not difficult to get done I think, it’s just that it took quite some time before all the boxes had been ticked and the approval was granted.
CP