Log in to Canvas and go to Grades.

Click on Export > CSV file.

In this CSV file, delete everything below row 3. You can also delete everything to the right of column E (Section), apart from columns corresponding to the scores you're about to import (if they exist).

Open the scores spreadsheet which you downloaded from WeBWorK.

If you want each homework assignment to be worth the same amount, then you will have to manually rescale each column to be out of the same total. If you rescale each column to be out of 100, you can then set Canvas to display scores as percentages. After rescaling each column, be sure to copy your columns and paste them as numbers (not formulas).

Instead of separate columns for “First name” and “Last name”, you need one column for “Last name, First name”. A formula such as =CONCATENATE(C8,“, ”,D8) should accomplish this. After making this column, be sure to copy this new column and paste it as text (not formulas).

Copy the “Last name, First name” column and all the scores columns to the template spreadsheet from Canvas. Every other column can remain empty.

If you haven't already created the corresponding homework assignments in Canvas, then in rows 1 and 2 of each score column, enter an assignment title and the total number of points.

Save the template spreadsheet, which should now contain scores.

Back in the Canvas gradebook, click “Import”.

Select your modified template spreadsheet and follow the onscreen instructions.