I reported that user nearly a couple of hours ago, for necro-bumping a 2013 thread just to spam a link (as did the user in all his prior posts). That’s more or less what how I reported, and simply reporting it should be enough really. It's still unhandled, but less than two hours have gone by yet since the report was made.
Since only staff members can remove posts, and there are only a handful of staff, it takes a while before the first staff notices the moderation report. But many users filing reports to staff during that timeframe increases the chance of it getting handled quicker as soon as the next staff comes online, since there would be many reports to the same thread in the backlog, which makes them look more accurate.