Step 1: Identifying the Sentence Structure.
The given sentence uses the superlative degree "most beautiful" to describe Renu, stating that she is the most beautiful among all girls in the locality.
Step 2: Changing to Comparative Degree.
In the comparative degree, we compare two things or individuals. To change to comparative, we modify "most beautiful" to "more beautiful."
Step 3: Converting the Sentence.
Renu is more beautiful than any other girl in this locality.
Final Answer:
\[
\boxed{\text{Renu is more beautiful than any other girl in this locality.}}
\]