Many citations use the Cite web template, or any of the other Citation Style 1 templates. All of these have an archive-url, archive-date and url-status parameter. Simply add these to the citation.
archive-url is of course the url to the Wayback Machine (or another archival website)archive-date should be set to the date the webpage was archived, preferably in the same date formatting as the existing date parameter.url-status should be set to either dead, live, unfit, or usurped. If the original URL is still available, set it to live, otherwise, set it to dead. This will change which of the links (archive-url or url) is linked to first in the rendered citation. If the original link is no longer suitable at all (perhaps because the someone else owns that domain now) set it to unfit or usurped, which will prevent the original link from rendering at all.
For the Citation you mentioned, you can see in this diff how I've done this. Note: url-status used to be dead-url, which has been deprecated. My edit from July 2018 has been updated in September 2019, see this diff.
