Hello Christopher,
Thanks for writing in! WordPress post/page contents and settings are saved into the database. When you do a backup, the WordPress core files, theme files, all plugin files, and the database were made a backup. Regretfully you cannot simply open a single page manually because its contents are still in the database backup. You can only do it if you do have access to the database.
Editing a backup file is not recommended. You might accidentally break something which can invalidate the backup file and will no longer be useful.
Hope this helps.