RENT to POOP.

Every letter change

1. RENT → BENT: change letter 1 from R to B.
2. BENT → BEAT: change letter 3 from N to A.
3. BEAT → BOAT: change letter 2 from E to O.
4. BOAT → BOOT: change letter 3 from A to O.
5. BOOT → BOOP: change letter 4 from T to P.
6. BOOP → POOP: change letter 1 from B to P.