Use some imaging software to copy the old drive exactly to the new drive. You may be able to use the Win 7 backup feature for this. I do know if you use Acronis you need to a sector by sector copy to keep the drive alignment correct for SSDs.
For neatness make sure your boot drive is port 0 or 1, and your BIOS is set to boot from that HD.
When you're back in Windows, check that it's booted from the correct drive in Disk Management and then you can format the old drive to use for data/storage or even take it out if no longer needed.