Searching google with "Cyberhome DVD 300 region hack" found the info easily.
I copied the below from www.videohelp.com:

"What I did with mine to make it region free is Switch player on and make sure there is no disc in the tray.

Close tray and press menu,1,9.

Change the region to 0, click enter and click the Eject, this closed the menu... The settings stay even if I remove the power from the device.

I have tested with:
Region 1 NTSC
Region 2 PAL
Region 3 NTSC

The DVD handled the PAL 50 to NTSC 60 conversion in colors with no problems.

Since this unit is being sent as a christmas present for some relatives in Europe, I tested this DVD player setting it as PAL and tested it to play both NTSC and PAL movies in this mode, both of them worked great and where in colors.

To add to that, this unit is great because it can handle 110 - 230 Volts and 50/60 HZ."