To import slides from a PowerPoint or Keynote (you must save Keynote as a PDF file first), choose Import Slides from File in the Modify Lecture window. You can also add slides using the Import Slides drop down menu found in the Prepare interface.
Browse to your file and once your file is 100% loaded, choose Import.
Note: When slides are imported into LectureTools, they are converted to static images so any slide animations will be lost. Any edits to slides will need to be done in the application you used to create your presentation.