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

Example Input: Sentence: 'a man in a baseball uniform posing outside of miller park'. Replace the letter 's' with 'h' in the sentence.
Example Output: a man in a baheball uniform pohing outhide of miller park

Example Input: Sentence: 'a person that is sitting under an umbrella'. Replace the letter 'a' with 'l' in the sentence.
Example Output: l person thlt is sitting under ln umbrelll

Example Input: Sentence: 'two police riding horses on a london street'. Replace the letter 's' with 't' in the sentence.
Example Output:
two police riding hortet on a london ttreet