Are you using photoshop 7 or later? I believe they added both the Patch Tool and Healing Brush Tool in Photoshop 7 and improved the Patch Tool in Photoshop CS.
- Zoom in on part section you want to work on. Click on Patch Tool (have source selected on the option bar at top). Draw circle around blemish.
- Drag circle to blemish free area.
- Release.