Need help with 42 inch LG monitor settings.. please!

[Blaze98]

Ok guys i need some expert advice!, my monitor that i bought used im sure has a decent amount of hours on it and a little burn in, but since i've had it a week the original burn in image is gone!, but now after playing a ps3 game for 2-3 minutes where there is a image that stays in one place, after i turn it off or change to something else the faint image is still there on a dark screen. im sure this is some sort of IR (image retention). What i need is help on what settings this monitor should be set at, like should it be set to XD mode? should it be set to daylight,night time, warm, cold, contrast brightness ect. I know tv's are different but i dont have a manual and have not ever messed with a plasmas before any help would be awesome!
i looked in the calibrate your tv thread and could not find anything for my tv