There are many ways to Paint it…but first it should be Primed with an Oil Base Primer… then sanded lightly, then Painted with either Acrylic or Oil Paint, using a BRUSH…

BUT… another method that works well, is to (after preparing the stained surface, by wiping with Lacquer Thinner, to "soften" and remove any sealers or coatings and using wood fillers, light sanding etc.) …simply Spray Paint it using Rustoleum's Painters Touch 2X Paint (it has a primer already mixed in with the Paint)… you can achieve a very SMOOTH Lacquer-like finish this way… assuming you know how to Spray using Spray Can Paint… Good Luck!