removing the paragraphs tags if paragraph starts with lower case

Hi everyone. I have an old book a friend gave me and the paragraphs are all messed up. I'm trying to clean it up and it would be amazing if there was a function like "merge with the upper paragraph if the current paragraph starts with a low-case word". Is there something like this?
Is there otherwise a way to change directly in the preview without going into the html editor? It's easier to remove a the space between paragraphs than tags...
thank you for your help