Starting with Astrid Pro

I’ve just paid around 250$ to get all the themes including this theme.
I went to documentation to see how to start using this theme, sadly I didn’t get it.
I’m new at this thing, which program/website that they was using to edit this theme?

I finally found which program/website to use for using this theme.
but I found a problem when I was instating the theme
The package could not be installed. The theme is missing the style.css stylesheet.
It happened when I was installing Astrid Pro, when I tried with Astrid it was ok

Any help?

Hello there,

Thank you for your purchase. Astrid Pro is actually a plugin that adds pro features to standard (free) Astrid. To install it to your site, go to plugins administration panel under the Plugins menu at the left side. Then install the .zip package of Astrid Pro to Add New plugin.