delete old course data

I’m looking for help creating a sql statement to delete completed course data that is older than 2 years old. I have a Sensei site that have been operational since 2014. That’s right, I have over 10 years worth of completed learner data. The comments table has over 3M records.

It is really slowing my site down.

Any ideas on sql statement to clean it all out.

I don’t want to delete the woocommerce purchase data, just the course completetion data.