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

Example Input: Sentence: 'this is a cute dog sticking his head out of the window of a red car'. Replace the letter 'e' with 'z' in the sentence.
Example Output: this is a cutz dog sticking his hzad out of thz window of a rzd car

Example Input: Sentence: 'a woman is playing tennis on the tennis court'. Replace the letter 'r' with 'z' in the sentence.
Example Output: a woman is playing tennis on the tennis couzt

Example Input: Sentence: 'a group of bikers in the rain walking toward their motorcycles'. Replace the letter 'n' with 'x' in the sentence.
Example Output:
a group of bikers ix the raix walkixg toward their motorcycles