Boot Camp to replace previous Mavericks partition

I have a 2011 MacBook with an old partition containing Mavericks and a larger partition that I had reserved for Yosemite. Yosemite's running great, and I would like to install Windows alongside it. All guides appear to indicate that BOOTCAMP must be a second partition and that the OSX partition must be the first. Without messing around with reFIT and a lot of manual unsupported futzing, can I manually format the Mavericks partition, cause the Yosemite partition to grow over the previous partition, or otherwise somehow do what I wish without backing up the Yosemite partition, restoring over the whole drive and starting from there? I'm willing to do that, just looking for a shortcut using what I have. As a bonus, I have the NTFS driver from my Seagate external drive, so I can partition to NTFS from within Disk Utility.