Thanks to above commenters. Can confirm I was able to do a button repair without soldering. Thank you all!

I don't see why you should remove these screws now, rather wait until your ready to remove th board at step 12. I followed the guide in order and when I used force to get the home button cover off all the buttons fell out. If the screws are.kept in the it's held together

It's cumbersome but avoids soldering which I'm not experienced with and worked to replace the button membrane for me

I didn't need to remove them. Leave the triggers on and saved some effort