You could use

git add -p <path> 

to stage the chunks that you want to keep in a particular file, then

git checkout -- <path> 

to discard the working tree changes that you didn't want to keep, by checking out the staged version of the file.

Finally, you can use

git reset -- <path> 

to revert the staged version of the file to the most recent committed version of the file to leave you with your changes unstaged.

You could use

git add -p <path> 

to stage the chunks that you want to keep in a particular file, then

git checkout -- <path> 

to discard the working tree changes that you didn't want to keep, by checking out the staged version of the file.

Finally, you can use

git reset -- <path> 

to revert the staged version of the file to the most recent committed version of the file to leave you with your changes unstaged (if you don't want to commit them).