Hi good folks on the forum

I am wanting to overseed the lawn which I started on September 21. When I seeded this new lawn initially on Sept 21, I put down the straw after seeding. In about 6 weeks, the lawn has come up- thick in some areas and thin in other areas. I want to overseed the entire lawn, especially in the thin areas. My question is how do I do this while there is start already on the ground- how will new seed make contact with the ground?

Do I need to remove straw? This will be a big exercise as I really don't know how I will do this for a large area.

Also, is it too late to overseed now? I am in Indiana.

Any thoughts?