You can complete all your reviews from the My Reviews Dashboard.
Use the Edit button on the left hand side of each submission in the table.
This will take you to the review form:
The form has a series of questions.
There may be more than one page to your form so make sure you answer all the questions.
You can view the submission by clicking on the Open Submission button at the bottom of the form.
The Open Submission button may have different text depending on what you are reviewing e.g. Open Proposal*
Answer the questions and then click on Close
Any changes that you do will overwrite what you have uploaded using Offline Reviewing.