We'll keep track of whatever thing hit your lemon with a local variable. We'll call the variable "character" and then set it equal to "other." (Remember, "other" is whatever "other" object ran into your button.)
Roblox is kind of silly - when an object is touched by a character, the object thinks it only got touched by the arm, and not the entire body.
If we continued with this code, we wouldn't be able to access the leaderstats, because those are being stored in your player... not specifically the player's leg.
In Roblox, a character's body is a parent of their arms and legs. So, make your "local character" equal to the "other.Parent."
We still have to double check that it was a player that hit your object. All players in Roblox have something called a "Humanoid" on them, and it holds all the information of your player.
So, tell your "character" to run a function called "FindFirstChild" with the parameter "Humanoid"