I downloaded Tesseract 3.02.02, windows installer version and extra files from here link textThe two files are "tesseract-ocr-setup-3.02.02.exe" and "tesseract-3.02.02-win32-lib-include-dirs.zip"First run the .exe, during installation when given options, tick the box for developer files; these include Leptonica source files.Once the install has finished, unzip the .zip file and copy the contents to the matching Tesseract installation directory.Some of the files will be the same but some will be extra source files.That will be Tesseract and source files for Tesseract and Leptonica on your system.There are lots of videos on youtube and guides on google for how to use CMake to build opencv with extra modules inc Tess and Lept