5 - 30 minuten
My 13" MacBook from 2010 was really, really TIRED. The battery, specifically, was worn to a frazzle. It would barely keep a charge for 30 minutes, and that was if it was in standby. Just gasping for breath. And, while I was at it, I thought a bigger hard drive would be great, because my iTunes library is really out of control, and there's just never enough memory anywhere for me, in life or digi-life.
I've never replaced hardware before, I don't think. At least, I don't remember ever having done it. (See comments on memory, above.) But reading the instructions on iFixit made me believe I could accomplish these tasks. This is the sort of thought process that has led me to much disaster before--thinking a task looks manageable, diving in, and then realizing I'm totally in over my head. So I anticipated serious potential harm would come to me and/or the MacBook. I tried to be systematic and work slowly, following the instructions for both the battery and hard drive replacement, since I decided to attempt accomplishing both at once. (This is the kind of decision that usually gets me in trouble.) Took me about an hour and a half from start to finish--not including the hard drive backup I'd done the day before--and...it was FLAWLESS. Seriously. Getting all the screws in and out of the case was the most challenging step in the whole process. Amazing. EVERYTHING WORKED THE FIRST TIME. And the new hard drive even came with an external drive case with a USB connector, so all I had to do was boot the laptop from the external drive, copy it to the new internal hard drive, reset the boot setting on the MacBook...and it was DONE. Obviously, I am BRILLIANT. But I'll give some credit to iFixit for helping me to see my own potential...
This might not be good advice, but I discovered I didn't really need to backup my hard drive before I replaced it, since the old hard drive worked fine with the external case/connector. So I might've been able to get by without spending $80 on an external hard drive just for the purpose of the backup. However, that only applied because there wasn't anything faulty happening on my old hard drive--I just wanted more storage. If I'd had a faulty hard drive, then the old one would've been useless, and that backup would've been critical--so it just depends on your specific needs/circumstances.