So the -k option (or --convert-link) will convert links in your web pages to relative after the download finishes, such as the man page says:
After the download is complete, convert the links in the document to makethem suitable for local viewing. This affects not only the visible hyperlinks, but anypart of the document that links to external content, such as embedded images, links to style sheets, hyperlinks to non-HTML con- tent, etc.
So, if I didn't specify -k, can I run wget again after the download and fix that, and if so, what would be the proper command? My guess is wget -c [previous options used] [url] and run it in the same working directory as the file were downloaded to.