I realized after I read my first post here that I'm making some assumptions.

I'm assuming you've tested the proc thoroughly.

I'm assuming you have a rollback script, so you can undo the change if it becomes necessary.

I'm assuming you have backups of the production database that can be restored if something goes horribly wrong.

I'm assuming you've coordinated the deployment with anyone else in IT/IS and with management.

Have you done those things?