Amazon S3 Permission problem - How to set permissions for all files at once?

I have uploaded some files using the Amazon AWS management console.

I got an HTTP 403 Access denied error. I found out that I needed to set the permission to view.

How would I do that for all the files on the bucket?

I know that it is possible to set permission on each file, but it's time-consuming when having many files that need to be viewable for everyone.