Moved here as this isn't about Linux Mint.
I'd imagine all you have to do is insert Windows 8 installation media, boot from it, follow installation steps and it will replace any other operating systems installed. For help with Windows 8 installation you can use a forum like http://www.eightforums.com/
DBAN would work fine to remove Linux Mint before installing Windows 8 (the drive would appear empty), but indeed it might not effectively wipe the contents of all the SSD's internal memory cells and data of yours might survive DBAN for recovery by forensic analysts. If that is a issue, look into whether your SSD supports the secure erase command (and it isn't a dummy command, as on some SSDs), which would securely erase all the SSD memory cells.