Samsung CLP 550 - Manual (Page 261)

I NSTALLING P RINTER O PTIONS F.3
F
3 Remove the two screws holding the metal plate in place,
and then remove the metal cover, as shown below.
4 Locate the memory DIMM slot (the upper slot) on the
control board.
5 Open the lever on each side of the memory DIMM slot all
the way.
Memory DIMM