To perform a review, you'll first need to log in.
Once you've registered as a reviewer, you'll know you have an assignment when you receive an email from the editor. The email will include the deadlines, giving you a good indication of whether you'll have the time to do the review.
To do the review, you need to login to OJS and select your role as a Reviewer.
Hit the "Active" link, from here, you'll see the assignment listed
Select its linked title to see the details.
Follow all review steps: