How to clean install Windows 7 (64 bit) on Alienware 14 pre-loaded with Windows 8.1?

Hi all,

I've recently purchased an Alienware 14 and in Singapore there's no option of selecting Windows 7 with it. I have a copy of Windows 7 on USB and would like to clean install over the existing Windows 8.1 that came with the laptop. I've read read several threads in this forum and managed to get the laptop to load up the Windows 7 installation. At the disk selection portion there're 2 disks and several partitions. I understand that the 80G mSata SSD is not meant as a boot drive and so I'll be installing it on the 1TB 5400 drive and use the mSata as a caching drive. What I'd like to know is, do I simply delete all existing partitions on both disks and simply create a partition on the 1TB drive? Or is there something I should be aware of when partitioning so that I can take advantage of the mSata as a caching drive post Windows 7 installation? Or I shouldn't even be attempting to do this at all?

Thank you for any replies/advice in advance.