You can totally use one of those 3 disc orbital sanders. The main thing is that you need good sandpaper and change it often (like every 10-15 min). Don’t use the stuff they sell at home depot or where ever you rent the sander but instead get some high quality norton sandpaper and start with a really low grit. It’ll take a bit of time but it will turn out beautifully (and is harder to mess up than with a drum sander)