There is really no need to adjust the size of the page or margins as the content will cut off automatically at the last placed element at the bottom. The templates are setup at specific sizes & have specific margins so that the Plugin knows what device it is exporting for. At this point, in order to reset your templates if you have saved over them, you will want to reinstall the toolset from our website. http://magplus.com
Let me know if you have any further questions.
Mag+ Support Team