Moving everything after or before a certain character

I know this is probably simple, but I'm not a scripter. I have files that have names like something-anything.som or nothing-everything.som. I'd like to rename them so that they are like this anything-something.som and everything-nothing.som. I know it's easy, but I haven't the faintest idea where to start.
Cheers

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Reply to #1:
Try do use the replace method and configure it like this:

Text to be replaced: (.*)-(.*)
Replace with: \2-\1
Use regular expressions: Checked
Apply to: Name

This will swap the parts divided by -.

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Reply to #2:
Perfect. I knew it was simple. Thanks alot

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