What are the nuances in the changed meaning behind the two following sentences when only the last sentence is changed into the other? [closed]

Solution 1:

In 1) the first and second sentence are redundant. The first sentence establishes what the writer has to do: kill her. The second sentence is answered by the first. What you should do is kill her.

In 2) the second section requests specifics of how to carry out (execute, if you will) the task mandated by the first sentence. "I have to kill her" and then "how (to kill her)".