@sfmyers common procedure for the screen replacment is usually removing the motherboard due to the heat application. The screen can be replaced without that but it makes it somewhat more difficult, since the heat can damage the battery as well as the motherboard. Commonly you would repalce the screen with the midframe to ensure the display does not crack.
If it would be my phone, I'd replace the motherboard. It just has a greater chance to work and less chance to break the display. Use these guides Samsung Galaxy S7 or something like this video
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