According to the NCERT text and Figure 11.9 representing the Hatch and Slack (C4) pathway, the process involves three major steps labeled in the diagram: 1. Fixation of atmospheric CO2 by Phosphoenol pyruvate (PEP) in the mesophyll cells. 2. Decarboxylation of the C4 acid in the bundle sheath cells to release CO2. 3. Regeneration of PEP from the C3 acid transported back to the mesophyll cells.