Please help a renaming problem

Hi, I am new to Hazel and I have a problem i can't get my head-on...
I have a folder with files using the following pattern "1234567_12_12345"
I want Hazel to watch this folder for new content and rename the files to just the first section i.e.: "1234567" removing the "_12_12345" example.
Any help would be greatly appreciated.
I have a folder with files using the following pattern "1234567_12_12345"
I want Hazel to watch this folder for new content and rename the files to just the first section i.e.: "1234567" removing the "_12_12345" example.
Any help would be greatly appreciated.