Nothing. Don't do anything.
When I get feedback from anyone who has read my WIP, whether positive or negative, I don't act on it - at least not for a while.
During our first crit group meeting, while I was shoving cookies in my mouth to keep myself from talking and/or bursting into tears, I was taking it all in. Listening and automatically sorting the feedback into categories: a) WHAT? That's not what I meant! b) OH! that makes it sound better than I meant, followed quickly by c) UGH! That's much worse than I meant. and finally d) I don't agree with that at all.
So, suggestions are made, places highlighted where I should revise. I take notes, Greg and Laura give me notes and I think about it all on the drive home while listening to Ultra Vivid Scene.
Then I put all the notes and annotated handouts in my drawer and stop thinking about it.
This is a riff on what Stephen King, in On Writing, says to do once you finish the first draft of a novel - put it in a drawer and leave it the eff alone. Let it marinate, let it simmer, let it percolate - whatever Food Network-ism you want to use. Just don't DO ANYTHING. Because at this point (either after a crit or after you finish your first draft ) you are vulnerable. And you don't want to make changes from a place of weakness, when you're sore from hearing things you don't want to hear or exhausted from finally finishing the effing thing.
After I finish my first draft, in about 20K words, I'll go back and consider the feedback. In fact, since I probably won't finish it before our next crit in three weeks, the next submission Greg and Laura get will have all the lovely and unlovely things (and some new ones) that they encountered in the first 4k words. But I'll be looking forward to their insights all the same. Soon they'll help me make my book better.