MySQL Upgrade on Windows

I am having MySQL 5.1 installed on windows box. Now I would like to upgrade to latest MySQL 5.6 version. I am planning to install MySQL 5.6 in the same server with same port 3306. After installation, I will map the new installation data directory to the older data directory which is used by MySQL 5.1. After this, I will upgrade using mysql_upgrade.exe. Will this plan work out or not ? Also let me know if any precautions to be taken care. Edit: This is production server and the DB is of huge size 100 GB, so we are not able to go with backup and restore mechanism which is time consuming process.