Note: if your Pixel 5a has experience the motherboard failure problem (suddenly "bricked" with no warning, unable to turn back on), refer to this Google support page for information about free service under the two-year extended repair program: https://support.google.com/pixelphone/an...

You will have to initiate a service ticket with Google before sending your phone to uBreakiFix.

Well done, thank you and the very helpful commenters! I completed successfully in about an hour. I could not shut off my phone, so it was on the whole time and did not go through screen recalibration. I restarted and it booted as if nothing had happened.

But...my phone is two parts lighter: the connector bracket and screw :P Hopefully the connector is well seated and hopefully I won't drop it again so it won't become dislodged. Re-seating the new screen went way too smoothly for me to bother opening it up again unless I have to.