How do I tighten mushroomed-out screws on my balisong (butterfly knife) ?

I have a fairly low-quality balisong trainer knife and its screws have become pretty loose now (after 2 months).

Aside from placing it on a flat piece of stone (or marble or metal) and carefully “hammering” the screws to tighten them up (which did not work for me), is there another way to do this?

It’s a trainer knife made by Ronin Gear. I am considering buying a decent one. But until I save some cash, I want to flip using this knife.

P.S. I can get by using this knife, but the loose screws just annoy me and I’m looking for a fix-up for it.