I've done a handful, some brands/models are more tedious than others. It helps to have a handful of tools that cost far more than the replacement of that screen. The $7 kit is not likely different than the $30 one, most likely that seller is probably labeling it as "genuine" or OEM and could be full of shit.
Heat gun (maybe can get away with a hair dryer or even torch) and plastic/nylon pry tools would help.
Watch all the videos for your given model. If not comfortable with this type of repair it may be worth taking to one of those cellphone repair stores but that would only be if upside down on whatever the cell company is charging you to just move to a new phone.
I did it myself on an old Droid phone some years back. It wasn't perfect, but worked well enough that it let me ride out the rest of my contract. This was back in the day when you got a free (or nearly free) phone from your carrier.
Now, I just have the accidental damage protection plan and get ass-raped by the deductible when I need to use it.
Just be prepared to plunk down the cash for a new phone if you screw it up worse than it already is.
I have a droid XT 912 that is seven years old, but I've been continuously updating with Custom Roms. The corner of glass has a crack, not the LCD, and the battery seems to be fine with close app monitoring. I'm wondering how hard it would be to replace the glass and battery.