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

Example Input: Sentence: 'a ski slope consisting of several people wearing skis and snowboards'. Replace the letter 'e' with 's' in the sentence.
Example Output: a ski slops consisting of ssvsral psopls wsaring skis and snowboards

Example Input: Sentence: 'this is a tennis player getting ready to serve the ball'. Replace the letter 'h' with 'y' in the sentence.
Example Output: tyis is a tennis player getting ready to serve tye ball

Example Input: Sentence: 'a man stands with his bike on the sidewalk'. Replace the letter 'l' with 'h' in the sentence.
Example Output:
a man stands with his bike on the sidewahk