Print each file twice to make 4 x build plate stabilizers (i.e. the .stl's have two of each part).
Lower Part: Print with supports on but no raft required. 3 shells 35% fill. Remove support cleanly as a flat under surface is required for the best effect.
Upper Part: No supports but print with raft for easier removal from the build plate.
Screw each half together and insert under the build plate and slide along the plastic beams. Position one stabilizer per corner.
LEVEL YOUR BUILD PLATE AS USUAL BUT STOP AT THE 7TH POINT...
Gently adjust the stabilizers up until they just make contact with the underside of the build plate... just a small amount of tension is required. This should not affect the levelling of the build plate but will eliminate any rocking during printing... and that is the common cause of corners lifting and prints warping.
Tighten the build plate down (i.e. tighten each of the three build plate adjuster screws) onto the stabilizers by 1/4 turn each to firmly lock them down.
CHECK THE LEVEL AT THE CENTRE OF THE BUILD PLATE IS UNCHANGED AND AS USUAL
You can change the stabilizer tension and adjust (tighten) during prints as vibration may loosen them a fraction. However, they have proven extremely effective in improving print quality and eliminating edges lifting and print warping.
Every Replicator 2 owner should print and install these...

Note: A few Replicator 2's appear to have been assembled with the build plate positioned closer to the mounting platform than most. If these do not fit your Replicator 2 that is the reason. Either reinstall your build plate platform or this will need to be modified to suit... worth the effort as this will greatly improve larger prints in particular.