If you don’t know iFixit.com you should immediately click the link and check out their website. They do not only offer repair guides for like every single Mac, other computers and other stuff in general, they do also sell hardware parts and tools. Even more importantly: They are usually the first ones to disassemble new products and determine a so called repairability score. They do even ship all their products all the way to Germany. And they care.
Back in 2010 I ordered a new case for my just sold MacBook Pro (to our friend and designer Lars) and they sold it for like $400. Our local hardware dealer Gravis made an offer to replace the case for like 1,200€ (no joke!). Besides that, I got all the fancy tools you need to take apart a Mac from them.
Today I checked their website for the removal of the optical drive on the MacBook Pro I mentioned above. As always, very helpful.