I recently asked this question and got some good answers, in one of the comments DVK mentions that reputation can be recalculated, and Gilles then provides a link to do just that.
When using Gilles’ link I do get to a page where I can select a recall button. I cannot, however, find a link to this link off the main site. (It might well be there, but I couldn't find on the reputation page where I assumed it would be.
So is this option freely available to everyone? If so, where is the link?
There is no link from the main site: it's a power user feature for those in the know, hidden because it's not a normal thing users need to do and recalculating reputation is a bit of an intensive process.
Nevertheless, it is freely available to registered users who know the link: the reputation recalculation button, however, only works once every 24 hours.
Like Mark said, It's a hidden feature. Someone on MSO pointed me to this list of other hidden features:
Before you trigger a recalc, you'll want to make sure it benefits you.
