Samsung ML 2550 - Manual (Page 208)

P ROGRAMME I NSTALLING P RINTER O PTIONS F.3
F
Installing Memory DIMM
Additional printer memory option are provided on DIMM (Dual
In-line Memory Modules). This procedure is applicable to either
option.
1 Turn the printer power off and unplug all cables from the
printer.
2 Remove the two screws on the rear of the printer, then
remove the control board cover.