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I do a job where I work in a lot of different customer sites. I happened to drop my phone at a particularly inopportune place/time, and boom. Screen spider-webbed. No problem, it was still working. Worked like that for months. Dropped it once more, and it no longer worked. Screen was completely dead. So I decided to pick up a replacement LCD assembly and go for it. It's cheaper than a new phone would've been.
I found the repairs remarkably easy. There were lots of little pieces, so having a small tackle box or something to hold them in would've been a good idea, but I managed even without. All told, assembly+disassembly time was only about 30 minutes. Turned the phone on and the screen worked like a charm. So did everything else, so I must've I managed to get all the parts back in the right place.
Use a small magnet to keep track of your screws, or a tackle box as I previously mentioned to keep track of screws+tiny parts you pull out of the phone. It'll save you headaches. If you're clever about it you could even put the parts in the compartments in the order they need to be placed back in the phone - that will save you even more trouble. Also, if you have the means, take a couple of photos while taking the phone apart, so you have something to compare against as you reassemble.