You can rename or delete preset items, as well as create or restore libraries of presets.
Click Rename, and then enter a new name for the brush, swatch, and so on.
If the Preset Manager currently displays presets as thumbnails, double-click a preset, enter a new name, and click OK.
If the Preset Manager currently displays presets as a list or text only, double-click a preset, enter a new name inline, and press Enter (Windows) or Return (Mac OS).
Select a preset item, and click Delete.
Alt-click (Windows) or Option-click (Mac OS) the items you want to delete.
Mac: <User>/Library/Application Support/Adobe/Adobe Photoshop CS3/Presets.
Windows XP: [Drive]:\Document and Settings\<user>\Application Data\Adobe\Adobe Photoshop CS3\Presets.
Windows Vista: [Drive]:\Users\<user>\AppData\Roaming\Adobe\Adobe Photoshop CS3\Presets.
The default locations for saving/loading/replacing presets are hidden by default in Windows.