Hand pulling would be your best bet this late, unless you have just a tremendous amount of it. Its already gone to seed, so killing it off now would not really accomplish much. You need to kill it before it goes to seed. A couple applications of pre-emergent control next spring and summer will help keep it down.

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John - Zone 6

The best way to go about solving the problem is by seeding now. The cooler temps and fall rains will help the grass establish itself. If you wait too long the bluegrasses in the seed mixture will not germinate, they take 6 weeks. The ryes will take about 6 to 7 days, and the fescues 2 to 3 weeks.

By springtime if you seeded now, you should have an established lawn that you will be able to put down your crab grass preventer on.

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Mike Maier
aka
The Plant Doc

Our yard was nothing but crab grass, I dug the grass out adn then dug most of the roots out as well(starting yard from scratch)

Crab is very easy to handpull. No need for any tools. Also, you can overseed now to help fill in the thin areas and apply the pre-emergent in the spring. The grass has more than enough time to get established before first frost. Good luck.

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John - Zone 6