As in the title.

Is it a DLC you bought and installed or did it get installed with the Legendary edition along with the other DLC?

I don't have the dlc for my PS3 version but I imagine you should be able to delete your game data and then simply re-download and install the other dlc (if you have them) along with the Skyrim game data. You could keep your Skyrim save data but I suspect its going to be corrupted without the Dawnguard installed.

But yeah, uninstall the Skyrim game data and just make sure you re-install just what you want.

Delete your Skyrim Update. This deletes your patch and all your DLCs.

After, download only the DLC you want to use, and the patch of course.

There is no way to uninstall only one particular DLC, unfortunately.

And keep in mind if your "saves relies on content that is no longer present " aka Dawnguard DLC, you should definitely start with an new character,

otherwise you saves will be messed up, and your gameplay as well. !!!

Ah, I was wondering about that.

The whole game world has been modified by the DLCs. Wouldn't removing them cause damage in some form?

Good thing I asked first.

As he said, just in your current saves. Start a new one.

Yes, probably it will...

So, if you decide to remove any DLC, and you have saves relying on any DLC you probably have installed on your HDD, you will have problems.