you can also get them used to day by having a "play" after day time feeds, before going down to sleep.

"play" at 8 weeks is obviously going to be a lot more to do with talking, massage, rocking etc.

but during night feeds and changes, keep interaction to an absolute minimum - cuddle/kiss etc without getting them excitable, keep your voice very soft and low, and keep the lights off or very low, to not break the "night" atmosphere if possible.

HTH