how do i download the nude patch and get it to work? i've searched the help forum but couldn't find it

There is a "no mosaic" mod which works with just the base game, available here on MTS. However, in order to see anything when they're unblurred, you'll need additional skins and so forth which cannot be found here on MTS - they are on the adult site.

As far as getting mods to work in your game, please see: Game Help:TS3 Custom Content^wiki