Step 1: Manually set all the bits to the initial state you would like them to have.
Step 2: Manually change the bits in accordance with rules you have defined. For example, if you would like a register in the state {0000 0001} to change its state to {0110 0010} and you find that a register is set to {0000 0001}, then go ahead and change it to {0110 0010}.
Continue manually changing the bits until the Atanasoff-Berry Computer is in state that you have defined as "halted".
Step 3: Look at the state of the bits: that's the answer to the problem!