After commenting that I had left the piece out, I opened the macbook back up and put it back.. I realized if nothing else it is between the battery adhesive and the trackpad cable, protecting that cable, and it's probably Not Good for it to be adhered directly to the battery.. luckily the battery adhesive was still not very set and it was easy enough to pry back out. I had to take it all the way out to fit the metal plate back in. Took me another hour or so,

The metal plate was a little bent as I had mentioned, and there was a lot of balled up adhesive from the battery and on the other side a different kind of thin clear adhesive that i scraped off as much as i could and rubbed off the rest with alcohol. I pressed it down flat and some of the old adhesive helped keep it stuck down. You can tell which way it goes by making the hole align to the position you see in the photo in the guide, and note that the lip on the one side goes down. Up and running again, it is a success.

As other commenters noted there is (was!) a plate between the battery and trackpad. Mine was a metal plate but others have said theirs was plastic. Mine was damaged (bent) when it came out with the battery. I put everything back together without realizing I was leaving it out. I am not sure it's purpose. I am having no issue with computer or trackpad, the replacement appears to be a success. I wonder if a problem may occur over time without that plate in place, however.

at this point, having skipped removing All The Things and fresh off step 4, i pried up the battery with a couple plastic cards. harrowing but less harrowing than the alternative. i was being careful not to press in ways that could harm my display. it took patience and was a huge pain but it worked pretty quickly. cleaned up the remaining adhesive with 70% isopropyl alcohol.

I took the good advice of all you previous commenters and skipped to step 34.

I did not have any solvent but it just took some careful patience prying up the battery with a couple plastic cards.

i had no idea my battery was swollen until i opened the back case to replace it. the back popped up right away on its own as soon as i took the screws out.

Oops! I forgot to put any tape back. Does this tape have a critical purpose, in other words should I go to the trouble to pry the screen back off and tape it?

i came back to say- as easy as this guide and repair are to follow, i feel like i may have a bad part?

the screen stopped working at first and seemed to have something to do with the fit of the screen. it was coming up a bit on the top right and not seated fully. so i pried it up again, reseated the cable, and resealed the edges more carefully. since then it works better but seems like it stops responding correctly frequently. rebooting generally helps. but after working fine for a while.. the touch function will suddenly and quickly deteriorate until it just doesn’t work altogether, and then i have to reboot.

each time i connected the digitizer cable i tested the device before sealing it with adhesive. i don’t really understand what could cause the issue because it works perfectly for a while before randomly petering out.

excellent guide, thank you arthur! this was so much easier than my pixel 3 and dare i say.. just plain easy!! love the 3a for repairability!!

actually to clarify- i didn’t move the little camera spacer to the new screen- i placed it around the camera on the phone, where there was a little indent for it, and stuck it down with a bit of tesa strip, then applied more tesa strips around the edge of the phone before finally reconnecting and replacing the screen. the little plastic bit i encountered needs to be precisely placed around the camera so would not be a good idea to just stick it to the screen when reinstalling!

i had a little plastic piece around the camera (seems to just be a spacer) that i moved to the new screen. had to pry it up with a pick cuz it was stuck down good.