Final answer:
To perform ligand and DNA alignment in PyMOL, follow these steps: Open the application, double-click on the relevant PDB files, select 'Hide Conformations' for the ligand, and click 'Create' to generate the alignment.
Step-by-step explanation:
To perform ligand and DNA alignment in PyMOL, you can follow these steps:
 
 - Open the PyMOL application.
  - Double-click on the PDB files of the ligand and DNA molecules to open them in separate windows.
  - On the window displaying the ligand structure, select the 'Action on Create' option and choose 'Hide Conformations'.
  - Click on the 'Create' button to generate the alignment.