Originally Posted by max
It's sunny with sandy soil. I'm up for tossing in grass seed and soil.
Do you have a problem using toxic chemicals? The easiest solution is use a broad spectrum herbicide, like the ubiquitous RoundUp, wait a while and replant the grass. Seed should work fine since it is sunny. Another option would be to use something like CrossBow which will kill the CC and leave the grass. You could then overseed or just hope the grass fills in (will work better if the grass isn't very thin).
If you want to go without chemicals, then you are left with two less optimal options: weed the CC out, not that hard to do but will kill your lawn, or try to tinker with the soil chemistry (most have poor luck with borax, you are seeking boron). The problem there is that you will get rid of the CC, but you don't want to make the ground hostile to other, desireable plants and boron will be difficult to remove.