If it's a separately-mounted connector it's a bot difficult, you have some tiny pins to solder in a tiny space. If it's a board or assembly, it's relatively easier - remove the old assembly, replace it with the new one.
The trick is getting to it. At least the screen has to come off - with a heat gun - and if you're not experienced in doing that (removed and replaced at least 6 screens) don't even think of doing it yourself. Even if you don't heat-damage the screen, or remove it before it's hot enough and break it, you'll still have to buy a new glue pad to replace it. It get complicated, it takes experience (most technicians ruin their first half-dozen phones, which is why a shop that trains its techs always keeps a few old hones on hand) and it takes "touch knowledge" of when the sreen is just hot enough to remove it.
It's really not worth risking the phone to save $90. (The guys you see in the videos who are "doing their first one" have been doing it for a long time - if you know what to look for you see all the signs.)