Basically there are two ways to do it:
1. Using “Convert to H3 project” tool.
2. Using “File->Import files…” command.
Convert to H3 project
This tool is under "Helpinator” start menu group. When you run it dialog like this appears:
Source type – select type of the source files here. You can import:
1. Old Helpinator project
2. Compiled CHM file (if you don’t have the source for it).
3. HTML Help compiler project – if you were authoring CHM files using standard Microsoft tool – Help Workshop
4. RTF/HTML/TXT/DOC files – import variety of text file formats, from selected folder. To Import DOC files you need to have Microsoft Word installed.
Source – path to the source files or directory with source files (in case of source type #4).
Destination type – select type of Helpinator project to create. Single-file project stores all data inside one zip-compatible project file. “Multiple files” mode is better if you use come kind of VCS system in your project.
Destination – path to destination project. A filename or a directory path, in case of destination type #2.
Language – select default language for the project with imported data.
Click “Run” to start conversion. After it’s done you’ll be able to open destination project in Helpinator.
This command acts identically to the “ RTF/HTML/TXT/DOC ” option from above, but is more useful to import files into existing projects. Select path to the directory with files to import and click “OK”.