How to modify Lightroom 4 presets?

Question

I downloaded a few LR4 presets. One of them is adding some vignetting which I do not like. I do not see any vignetting applied in LR4 Develop Module.

Is there a way to remove it?

Answer 1

1. Apply the preset to an image
2. Modify the setting you would like changed in the preset
3. Click the "+" sign under the presets window to create a new preset, or right click an existing preset and click "Update with current settings"

If it is adding vignetting I would look at the Lens Corrections Develop module, as well as the Effects Develop module.