Renaming is called "moving" on wikis. That is because the old page title will redirect to the new one and technically the old title is not renamed.
To move a mix page, you must be logged in. Just click
[move] on the according page and correct the name (be sure it's correct this time!). All links in the database will be updated*, links which are posted somewhere else will be directed to the new page as well. If you rename your new title again, those links from the original page name will redirect to your first renamed title, not the second.
Before you move a mix page check what other pages link to it. If the tracklist state icon should be displayed on that page, it's better to link to the renamed title (otherwise it will link to the redirect page). To check, click "What links here" in the toolbox when you're on the mix page you want to rename.
Dates: We use the YYYY-MM-DD date format, but also use e.g. "1997 - Massive Attack - Novamix, 02-12-1997" since it's not clear if it's December 2nd or February 12th (used differently in US and in Europe). So we use 1997 in front only (ofr sorting in categories) as it's not wrong and the most correct we can do. Don't change such dates if you're only assuming the correction.
DJ & DJ: Use & only when the DJs really played back to back together. If they only play after each other use "DJ, DJ". Don't change such joiners if you're only assuming the correction.
You can find more information about titles here.
*In a category you may still see the old name. Read The page doesn't refresh?.