Yes, I agree, removing the cage makes it easier. After reinstalling the heatsink, I was able to reinstall the cage by cutting one side of it, which allowed the cage to be spread wider so that it could be reused. Once in place the screws held it into position. This upgrade was on my 2013 iMac which I upgraded from the base i5 to the i7 (4771) One thing I noticed is that the fan runs more because of the higher temperatures generated by the i7…I would say the gains were modest, but whether it is worth it….I am not sure.
I concur, opening the screen a 2nd time is considerably more difficult because the adhesive strips are thinner than the original, which makes getting the cutting tool inserted much more difficult….as a result unknowingly I elongated a small crack to a much longer crack and somehow, the LCD now has a wide grey strip from top to bottom….The first time opening was easy, second time resulted in a ruined screen.. The cost of. a replacement LCD is the same has replacing the entire computer….I would recommend anyone attempting to remove the screen for any reason, do not use the aftermarket adhesive strips if you ever intend to open it up; again, or cut the strips much shorter, or possibly use a few pieces of scotch tape or similar to hold the screen in place….since the screen tilts back, this should not be a problem…Good luck…