Google app invite tracking if you already have custom dimensions
<p>I would like to track Google app invites in Google Analytics. There is a guide how to set it up. One of the steps is the create a custom dimension. However it says:</p>

<blockquote>
  <p>Note that this dimension must be at Index 1 in the table of Custom Demensions</p>
</blockquote>

<p>Our GA property already has custom dimensions. So index 1 is already taken by another custom dimension.</p>

<p>How can we use a custom dimension that's not at index 1? Or how can we change the index of existing dimensions? Or how can we delete an existing dimension?</p>