To install one of the problem sets from this wiki to your WebWork course:

Uploading

From this site, click on the appropriate problem set desired and save to your computer
Log into the WebWork course for which you are the instructor
From the Instructor Tools, select File Manager
Make certain you are in the 'templates' directory. This is the default when you first access the File Manager but just check to be certain.
Click on the 'Browse' button located near the bottom of this page
In the popup window, browse your computer to find the file you downloaded arlier. It should have 'last name' '.tgz'
Make certain 'Unpack archives automatically' and 'then delete them' remain checked.
Click on the 'Upload' button

Unpacking

Now that the file archive is located in your WebWork directory, you will need to unpack the single file into separate homework sets.
From the instructor's Tools, select Homework Sets Editor.
Click on the 'Import' button.
Select 'multiple sets' and select the files you want to use. Since you are using the model course files, you likely want all of them. Holding down the control key and clicking allows you to select multiple files. Holding down the shift key and clicking the first and then the last files allows you to select them all.
Click on 'Take Action'