How to edit various styles on an Apple Template?

Hi,

I'm using one of the pre-defined templates that are available in Pages for iPad. However, I need to change the size of the text and the indent on one of the paragraph styles. However, when I click on the styles, the edit button in the top right corner is grayed out and I can't make the edits.

How can I do this? Why isn't edit avail;able? It just doesn't make sense. As it is, I'm having to manually change the text sizing chapter by chapter across nearly 30 chapters on a 330+ page book manuscript. I really would love to be able to edit those styles!

Thanks so much for any help! I really appreciate it. :)