In this task, you need to replace a letter in the sentence with another given letter.

Example Input: Sentence: 'a man getting ready to hit a ball at a baseball game'. Replace the letter 'n' with 'v' in the sentence.
Example Output: a mav gettivg ready to hit a ball at a baseball game

Example Input: Sentence: 'giraffe standing on a pile of rocks reaching up to a branch with its mouth'. Replace the letter 'g' with 'n' in the sentence.
Example Output: niraffe standinn on a pile of rocks reachinn up to a branch with its mouth

Example Input: Sentence: 'someone is cooking their hot pockets in the microwave'. Replace the letter 'i' with 'o' in the sentence.
Example Output:
someone os cookong theor hot pockets on the mocrowave