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

Example Input: Sentence: 'this is a seafood platter with lobster and corn on the cob'. Replace the letter 't' with 'z' in the sentence.
Example Output: zhis is a seafood plazzer wizh lobszer and corn on zhe cob

Example Input: Sentence: 'a man is somewhat hard to be seen in the wave, on his board'. Replace the letter 's' with 'b' in the sentence.
Example Output: a man ib bomewhat hard to be been in the wave, on hib board

Example Input: Sentence: 'a green truck is driving down the road'. Replace the letter 'v' with 'f' in the sentence.
Example Output:
a green truck is drifing down the road