Keep the type setting at Content-Aware, which means the tool will sample pixels and match the texture, lighting, transparency, and shading of the sampled pixels to the pixels being healed.
Click the Spot Healing Brush tool in the Tools panel or just press the J key. In the options bar, you can adjust the size and hardness of the brush edge (harder creates more clearly defined edges). Keep the type setting at Content-Aware, which means the tool will sample pixels and match the texture, lighting, transparency, and shading of the sampled pixels to the pixels being healed.