I would talk with the people at your local Rutgers Cooperative Extension office about control of this invasive grass species and plan on a 5 year program to get it under control. Tilling may bring some seeds to the surface but it may also bury others. Since this grass is quite common along roads and other places that have relatively poor soil this may be an indication of how it grows so well and out competes native species, so a good look at the soil may well be warranted now.

http://plantscience.psu.edu/research/projects/vegetative-management/publications/state-parks-invasive-species-management-quicksheets/4.-japanese-stiltgrass-microstegium-vimineum

A good reliable soil test from Rutgers CES for soil pH and major nutrients before tilling that soil would be a good idea, and a look at the soil with these simple soil tests,

1) Soil test for organic
material. From that soil sample put enough of the rest to make a 4 inch level in
a clear 1 quart jar, with a tight fitting lid. Fill that jar with water and
replace the lid, tightly. Shake the jar vigorously and then let it stand for 24
hours. Your soil will settle out according to soil particle size and weight.
For example, a good loam will have about 1-3/4 inch (about 45%) of sand on the
bottom. about 1 inch (about 25%) of silt next, about 1 inch (25%) of clay above
that, and about 1/4 inch (about 5%) of organic matter on the top.

2) Drainage. Dig a hole
1 foot square and 1 foot deep and fill that with water. After that water drains
away refill the hole with more water and time how long it takes that to drain
away. Anything less than 2 hours and your soil drains’ too quickly and needs
more organic matter to slow that drainage down. Anything over 6 hours and the
soil drains too slowly and needs lots of organic matter to speed it up.

3) Tilth. Take a handful
of your slightly damp soil and squeeze it tightly. When the pressure is
released the soil should hold together in that clump, but when poked with a
finger that clump should fall apart.

4) Smell. What does your
soil smell like? A pleasant, rich earthy odor? Putrid, offensive, repugnant
odor? The more organic matter in your soil the more active the soil bacteria
will be and the nicer your soil will smell, to a point. Too much organic matter
can be bad as well.

5) Life. How many
earthworms per shovel full were there? 5 or more indicates a pretty healthy soil. Fewer than 5,
according to the Natural Resources Conservation Service, indicates a soil that
is not healthy.

may also help.

kimmq is kimmsr

How big is the area that you're trying to re-seed? Seeding directly into dead grass and hoping for the best is not the most efficient way to do it. If it's a small area, you can lightly rake the seed with a garden rake to get seed to soil contact. If it's a larger area, you should use a slit-seeder which makes vertical cuts into the soil and deposits the seed in there--you can either rent them or have a landscaper that has one do the seeding.

Stiltgrass germinates in the spring so now is a good time to reseed with turfgrass. If you seed now and let the new grass get established during the fall, you can put down a pre-emergent in the spring (around April 15) that will keep new seeds from sprouting. Look for a long-lasting one like Dimension (dithiopyr) or Barricade (prodiamine). These can be bought in granular form at a Lesco landscape supply store and put down with a spreader, or you should be able to find a landscaper that's familiar with them. You may need to do another application in mid summer to get through the rest of the year.

Finally, if you do get stiltgrass in the lawn, there is a specialty herbicide called Acclaim Extra by Bayer (fenoxaprop) that has shown success in killing stiltgrass in lawns without harming the turf grass.

If you have any other questions, I have quite a bit of experience fighting this weed both in lawns and in wooded areas.

Agree with the last poster. In my research it seems as if the Bayer product works very well. Its on amazon here for like $25. If you have it though it is also likely you will need to use a pre-emergent in the spring as the seeds in your soil will persist for up to 5 years. Anyhow, the Bayer product seems cheap and easy to use (no mixing) and pretty foolproof for non-Bermudagrass lawns.