There are a couple threads about this on the forums. Deleting that folder and letting meteor rebuild it on the next project run is one option. Another is to simply reinstall meteor.
@sashko As this comes up again and again, I’m thinking that a spot in the guide for environment maintenance might be a good idea?
@vigorwebsolutions thanks for the help, I chose to re-install Meteor as per @glasser suggestion in a GitHub issue of a similar topic. It’s down to 1.01GB which is OK for now.