How to import threads with journal posts to Blogs?
 

I have several hundreds journal threads that I want to move to the blog.

However, the threads each contain a number of journal posts and comments.

The end result should be:
- one blog category named after each thread.
- one blog entry per journal post.
- each blog entry should be in the appropriate blog category.
- each blog entry should be in the Global category that relates to the forum. (only 5 forums, so can be done in 5 times if needed)
- the dates should stay the same.

How do I manage to import this?