If the rubber covers come off they are a pain to put back on - you have to slide the rubber into space between the RAM module and the retainer clips - this video explains it perfectly -

https://eshop.macsales.com/installvideos...

Tape the LED light indicator to the case to keep it out of way until reassemble.

Loosen the side nearest outer case first

Yes - Had to use a pliers to turn the T10 Screwdriver to get the first turn loosened!