I've a iMac 27" medio 2011 with a HDD. I would like to add a primary SSD and still keep the original HDD. I've contacted my local Apple Authorized Partner here in Denmark. The cost is about $720 to insert the SSD (not including the price of the SSD). The high price is because they have to replace the cabinet and add some new cablet. I've found this tutorial with a step-by-step guide for inserting a SSD and still keeping the original HDD. The trick here is to attach/mount the SSD drive to the DVD Drive (ODD). Is this a good and safe way to go? I have experience in assembling desktop PC's and have done battery replacement on iPhones -- but I have not done an operation like this before. How hard is it? One of my worst concerns is to get a lot of dust between the screen and the glass after the operation.