Niquelar means "to nickel-plate", which is the process of coating an object with a layer of shiny nickel. It is a very rare and specific verb to find in the lyrics of a song, making it quite unique.
In "Los Chismes", the singer responds to gossip that his beloved is dark-skinned by boasting, "Yo tengo mucho dinero y te mando a niquelar" (I have a lot of money and I'll have you nickel-plated). This is a wild and humorous exaggeration to show how little he cares about the gossip and to prove that he can make her shine brightly for him, no matter what people say.
Have you ever had people gossip about your partner? In "Los Chismes," Chalino Sanchez has the perfect response. The song starts with him barely mentioning he might get married, and suddenly everyone has an opinion on his choice of bride. They try to discourage him by listing her supposed flaws: she's a little blind, she's skinny, she's dark-skinned. But Chalino just brushes it all off with some of the funniest and most confident comebacks you'll ever hear.
He tells the gossips he wants a wife, not someone for target practice: "Yo te quiero pa' mi esposa / No para tirar al blanco" [I want you for my wife / Not for target practice]. When they say she's too skinny, he jokes that he's not trying to open a butcher shop. The best line might be his solution for her dark skin: he says he has enough money to have her nickel-plated so she'll gleam in the dark! The chorus makes his point crystal clear: "A mí los chismes / Me vienen flojos" [Gossip / doesn't bother me]. It's a bold and hilarious song about ignoring what other people say and loving someone exactly as they are.