Short Answer 
To remove an assignment submission in Canvas, log into your account, locate the course and assignment, and then navigate to the submission history section where you can delete your submission. Ensure to confirm your choice to finalize the removal.
Step 1: Log into Canvas
Begin by accessing your Canvas account using your credentials. Ensure that you’re logged in securely to avoid any unauthorized access. Once logged in, navigate to your dashboard to see all the courses you’re enrolled in.
Step 2: Locate Your Course and Assignment
Find the specific course that contains the assignment you wish to remove. Click on the course to open it and then head to the Assignments tab. Browse through the list of assignments until you identify the one you want to delete.
Step 3: Remove Your Submission
Once you have selected the assignment, look for the submission history section. Here, you’ll find an option or button to either delete or remove your previous submission. Click on it, and confirm your choice to successfully remove the assignment submission.