How do I use threaded inserts?
You need to pre-drill a large but shallow hole of the correct depth, and use the bit size recommended by the manufacturer for the material you are setting those into. Too small and you'll crack the wood/whatever.  Too big and they won't hold.   It matters.  

You might want to try on some scrap first.  

Did the supplier provide these nuts full knowing that you're going into formica?   Or is this a generic kit?