using VBA Vlookup to replace cell values?

For instance I have a column and a row

Pet Name Pet Age Price
Dog A 15 55
Dog b 20 100
Dog C 13 25
Dog D 12 23


So, I know how to use Vlookup and Match within VBA to retrieve the value, but How do I put the value back to the specific cell (where I grabbed it from).

For instance, say I know that this spreadsheet is wrong, I want to decrease the pet age by 2 of dog A.

I know how to retrieve the value 15 and deduct it by 2.

But my question is,m how will I put the value deducted (13) back to that cell?

Thank you!

Kind Regards,
Dinosaur1993

anyone? Pls help me, thank you!