1) Quick Import:
I have created a simple plugin which imports the bbPress dummy data on your site within a few minutes. Check below video:
Click on the download plugin to download.
2) Manual Download
- Go to Tools > Import.
- Go all the way down to where it says WordPress and click the link.
- If you haven’t installed the WordPress importer plugin already, click Install Now.
- If you have the WordPress Importer plugin installed and activated, proceed to the import process.
- Click the Choose File button, now select the file you just downloaded before.
- Click Upload file and import.
- You can now assign the posts to a specific user of your choice and check Import Attachments
- Now click Submit
- After that, it should import all of the posts in the file and tell you that it is done at the very bottom.
Source Creating Test Data