The easiest way to steal the election is to just reverse the Obama/Clinton counts on a precinct basis. If you do it in every precinct it even gives you plausible deniability - sorry, computer bug! A human error programming the mappings to the database.
But maybe they thought that's easy to reverse and they really want Clinton to win. So they say okay, let's just tamper with the largest county in the state. They could just have reversed the counts and, given statistical noise, the vote percentages would have been similar but to less than 95% confidence. Being a single county, you'd have to go down to precinct level to show all the precincts are switched.
But maybe they thought they needed to eliminate the discrepancy. In statistical parlance, they worried about a one-tailed chi-square test (misfit) but not about a two-tailed chi-square test (misfit or too-good-to-be-true fit).
I mean, it just takes a pocket calculator to get the "correct" vote counts.
Tampering with the count would mean that a recount would give the win to Obama. Tampering with the ballots would confirm the results, possibly with a 200-vote difference from the initial ones. We have met the enemy, and he is us — Pogo