What is Lady Macbeth's plan?

Lady Macbeth counsels her husband to "screw [his] courage to the sticking place" and details the way they will murder the king (60). They will wait until he falls asleep, she says, and thereafter intoxicate his bodyguards with drink. This will allow them to murder Duncan and lay the blame on the two drunken bodyguards. Macbeth is astonished by her cruelty but resigns to follow through with her plans.