I would just leave the SSD in, install Windows 7 on that and add the other drive after the install. There's really no reason to add confusion. Especially since the storage drive is already "in-use". That's what I did on my last reinstall.
If you download the Windows 7 software you'll have to use a third party program or service. Some people like going about it that way just to have a physical copy for later.
Otherwise,
PC worlds step by step guide should be pretty simple. I'll have to admit I like having Windows 7 on a USB drive as well, VERY handy
Sometimes if you call the warranty on the laptop they will send you a Windows 7 disc. Just depends