> "I used this site to upgrade my mid 2010 iMac to the fastest i7, SSD, 16GB RAM and a larger HDD."
That's good to know... I use Other World Computing (OWC) www.macsales.com for all of my Mac upgrades. They have excellent How-To videos on how to install all of their parts. I just ordered a 2.5" data doubler for my Mac Mini so that I can put 2 SSD's in it.
That video made me laugh when I think of people who claim that Apple just buys PC parts off the shelf and puts them in a box and charges more for them. Other than the CPU/GPU and hard drive, there was nothing in that 27" iMac that remotely resembles an off-the-shelf PC component. The same is true for Mac Pro's, Mac Mini's, and of corse MacBook Pro's. Apple designs all of their own hardware and it's amazing how compact they have been able to get things. A bit too compact if you ask me. I still have an older 2012 MacBook Pro because it doesn't sacrifice expandability and function for size.
Checkout the video on replacing the hard drive with an SSD in my Mac Mini (it gets totally disassembled!):
Gotta say that I love digging (gently) into complicated stuff, and YouTube is a wonderful teaching tool. From replacing a cracked screen on my phone, to replacing a car's heater-proportioning door (a VERY expensive task if performed by a repair shop), to replacing the cooling fan on a Dell 12" laptop, YouTube shows the way.
Wait, I need to go outside now while it's daylight and replace the turn-signal stalk on my SUV. It's one of those assemblies that does about 10 things, and YouTube showed me it's not that hard to do replace as long as you pull out screws and panels in the proper sequence. See? A great teacher.