>>8908566assuming there's gonna be some rotation around the peg so don't cut but slowly scrape off material with a blade while testfitting until satisfied.
a small strip of sandpaper works as well but make sure you don't end up doing pic related which will make the pieces want to separate during movement.
how big is the hole and how big is the peg? if it's like something going from 3mm to 2mm I'd just make a new peg with some brass.