My Mechanical Engineering PhD research work involves using my phone to control applications in a Virtual Reality system, as an Augmented Reality device, development of Qt for iOS applications, and to interface with a FLIR thermal imaging device. In other words it get's a lot of intensive use throughout the day. It held up quite well for the 2+ years of use but it met the requirements for getting a replacement. While I do a lot of programming, my previous degrees were in Mechanical Engineering and Industrial Engineering. I enjoy taking things apart and prefer to do tasks like this myself.
iFixit has been my hands-down favorite source for guides for years. Sure you can find all sorts of random videos and websites online, but why waste your time? iFixit may charge a bit more for their products, but c'mon their guides are free folks! Not only are the guides free—but they are some of the best around! The photographs are top-notch. They don't rely on just videos. Furthermore, I often find that you can use one guide for more than one task. For example you might be replacing the battery but in that guide their may be tip/trick or particular view that helps you with replacing the home button... Hence my story title...
The repair went a bit longer just because I was being so careful—not because the 45 minute time is inaccurate. Just trust the guide and go for it.
It would be nice to see some other ideas with pics for putting back the screen cables. I had to keep going back to one step to remind myself which sequence to use when putting the cables back. I ended up messing up the adhesive placement—the guides are more accurate for the iPhone 7. I must have done something because the home button didn't work after I got finished. I think I was not careful enough with the screen. I ended up opening and closing the screen at least 3 times. If I did it over I would just leave the original adhesive. The first time I opened the screen it was fine—so just give yourself time and do it all at once and the guide will work great for you.
I did the repair on old white t-shirt (clean) that was destined for my garage to clean my bicycles. The screws don't roll around and you can group them with the metal covers for quick reference. I originally drew a little diagram on a piece of paper but the t-shirt worked better. I couldn't find a rubber band so I used some a couple velcro cable ties to hold the screen to a multimeter. The multimeter had a stand to prop it up and (like most) was covered in a soft material that wouldn't scratch the screen.
Definitely pop off the Taptic Engine. Once you get a grip on 1 of the 2 adhesive strips for the battery, rest your forearm on the edge of the worktable and slide your arm as you pull the strip off at the angle suggested. If you look at the strips and they start to bubble don't stop just steadily pull and you'll get both strips off in one piece like I did.