Need to remove the "top

Question

Need to remove the "top cover" of my Compaq Presario 12XL400 (actually a 12XL426)to get to the power on micro switch. I can remove the palmrest, keyboard, heat sink, cd-rom, 2 hinge covers - but I can't get the U shaped top cover to come free.Any ideas??? - would love a link to a "service manual"Thank You,Doug