I have a Dell N5030 I inherited from our granddaughter when she decided she liked Apple better. She had been having issues with the HDD so I took it stripped off Windows and naturally put Linux on it. It worked fine for a while but eventually the HDD went out. I've been dragging my feet of replacing the HDD because you have to split the case to get at it and two I really haven't needed it. Then NewEgg made me a deal I really couldn't resist for a new HDD.
Well the new HDD came today so I split the case only to fine two ribbon cables with straight ends connecting the two together. I also figured that the HDD would be bolted in like all the other HDD's I've replaced. So I get on line and find out I have to pull the keyboard to get at the ribbon cables. So I pull the keyboard get the case split only to fine the HDD just slides into a socket and is not bolted in so I could have very easily slide the old one out and the new one in without pulling the keyboard or cables. So what should have been a 30 minute job at best took a bit over and hour. Once I had the cases back together then I had the new HDD up and running in about 10 minutes, updates took a bit longer.
So if you have a Dell, especially a N5030 you can replace the HDD by simply taking the screws out and just barely open the case and slide the HDD out. It is on the right side in front. Then slide the new on in and install your OS.