input question: To make a tomato sauce taste more like a pizza sauce,

output answer: mix a little bit of sugar into the sauce to sweeten it.

input question: To replace batteries in the game gear.

output answer: Using a screwdriver, remove the two battery covers and replace all 6 AA batteries.

input question: What is a good way to close a sale when the buyer is uncertain?

output answer:
Each sale is different, but often, buyers get cold feet because of fear of being ripped off. Be inquisitive and find out what they are afraid of, exactly, then you can address that specifically. Successfully addressing a buyer's fear depends on paying close attention to the prospective buyer's viewpoint, and once you understand where they are coming from, in most cases you can alleviate their fears successfully. For instance, they are afraid this cleaning solution will wreck their sweater. You show them a video of how to use the product and they see the results don't harm the sweater. Their fear is gone and you've likely got the sale.