KCBS-TV's top anchor team of Jim Lampley and Bree Walker will go to work a day earlier starting next month. In yet another attempt to boost Channel 2's anemic third-place news ratings, the station on July 9 will move Lampley and Walker to a Sunday through Thursday schedule, instead of the customary Monday-Friday work shift. The idea is to take advantage of CBS' strong Sunday prime-time lineup of "60 Minutes" and "Murder, She Wrote." During the May ratings sweeps, Channel 2's Sunday 6 p.m. newscast with weekend anchors Penny Griego and Ross Becker picked up the station's highest ratings among all of its news broadcasts. Station executives hope that having Lampley and Walker on view on Sundays will bring viewers back to the Channel 2 news the rest of the week. Sportscaster Keith Olbermann also will be on the Sunday 6 p.m. and 11 p.m. newscasts. KTTV Channel 11 tried the same Sunday-Thursday tactic two years ago when Fox Broadcasting debuted its prime-time Sunday night schedule, but has since gone back to the more traditional rotation.