Hello, I am looking for advice and links to any relevant tutorials as I am wanting to help my friend improve the speed of their Mac. They have an iMac 21.5-inch, Mid 2011 with a 2.5 GHz i5 and 8 GB of 1333 Mhz DDR3 memory. Its currently using OS X El Capitan Version 10.11.6 My plan is to: 1. Update their OS to the latest possible version for their hardware. I believe it is macOS High Sierra? 2. Install more RAM. My understanding is there is 4 ram slots so it would currently have 2 slots filled with 4GB sticks and I could double that by buying this specific model of RAM? 3. Thinking of using an SSD. Reading online it looks sort of daunting to install an internal SSD. But using an external SSD instead seems to be pretty straight forward and would still be much faster than the current internal HD. I believe I can use the thunderbolt port to connect it? What external SSD would be a good choice? I have been looking at this one. Thank you for any help.