There are a couple of ways that you can download a CSV list of your Discourse users. The easiest way is to go to Admin/Users and click the Export link. Once you have the CSV file, there are quite a few WordPress plugins that can be used for importing users from a CSV file. Search for ‘WordPress import user.’ You will get a lot of results.
I’ve looked at a few of the plugins. One difficulty you might run into is that they are expecting the values in the CSV file to be in a different order than the order they are in the Discourse users file. If this is the case, you could install the Data Explorer plugin and use it to create a CSV file that gives you the user data you need.