Honestly, I wouldnt make a move yet. Your team is doing fine. Probably faced Peterson, Brees or Chris Johnson in the last 2 weeks?
I just dont see who I'd drop there. Maybe Royal for Manningham.. but that's risky.
Team 1- Start:1QB, 2RB, 3WR, 1TE, 1K, 1DEF
QB: Delhomme, Schaub
RB: Portis, Westbrook, D Williams, Buckhalter
WR: Edwards, S Smith, Evans, R Moss
TE: Witten, Shockey
DEF: Tenn, SD