Once the old OLED and digitizer have been removed, make sure to clean up any bits of broken glass, dirt, adhesive, etc. that could prevent the new one from mounting properly.

Since it will be very hard to remove the new screen without damaging it once it's installed, it's a good idea to carefully connect the new screen before adding any adhesive or glue, and make sure the screen and digitizer work properly since most parts sellers won't take a damaged part back if it's broken.