Just completed this replacement now.

I'm in China, so i ordered a replacement screen on Taobao for about 300 RMB ($40) and followed these instructions.

Very clear guide, excellent photos and it really pointed out the mistakes not to make.

It took me about 30 minutes on my lunch break at my desk. And now my fully functioning phone is back - home button works, front-facing camera works, earpiece works. All good.

If you take your time, get the correct tools and follow these instructions to the letter, I think pretty much anyone could do this replacement.

Thanks to the author and other commenters for providing input.