As per many of the other answers, you can use git reset
BUT:
I found this great little post that actually adds the Git command (well, an alias) for git unadd
: see git unadd for details or..
Simply,
git config --global alias.unadd "reset HEAD"
git config --global alias.unadd "reset HEAD"
Now you can
git unadd foo.txt bar.txt
git unadd foo.txt bar.txt
Alternatively / directly:
git reset HEAD foo.txt bar.txt
git reset HEAD foo.txt bar.txt