Hello Matt,
Thank you for your patience!
Before we proceed with the task we would just like to clarify something first. Updating your theme is a simple operation, however, by doing this, a fresh copy of the latest version of your theme is added to your themes section. This fresh copy is a blank slate, and has none of your previous changes on it. The changes you’ve already made will not be deleted, but they will be on the old copy of the theme (which is currently live in your store).
In that respect, the term “update” can be misleading, since this is, in fact, an installation of a fresh copy of your theme, with the latest version.
It also implies re-doing all the changes you’ve made on your older theme, on the freshly installed one, from scratch, since there is no way to combine the two themes, or to “move” your changes onto the new one (the code isn’t entirely compatible) between the two versions.
Let us know if you’re OK with that please, and we can proceed to install your fresh copy of the theme.