You can use this same instructable to replace your hard drive with another hard drive, on the outside they are completely identical.
And by the way, I did this at TechShop (www.techshop.ws) as they have a whole bunch of really convenient large tables in the common area with some great lighting and you'll always find some available.
Step 1: Acquire SSD (or conventional HD) for replacement.
For this procedure all you need in terms of parts is the replacement SSD only. I will talk about tools in the following slides.