Clean install on AWS EC2 from GIT

I have an app running on the AWS EC2 instance and something went wrong on the last update. I generally ssh to EC2 server and do a git pull, where I have a remote repository.

How can I do a clean install from my master repository? Every time I do a git pull i get you need to resolve your current index first

Can I do a

git reset --hard HEAD
git pull

from the remote repo on the EC2 instance ?