Joomla currently provides one way of doing that, copying file manually.
There are two things you need to know.
Where are the original files. They are kept in the
media/com_ats folder under your site's
Where to put the overrides. You need to put them in the
where MY_TEMPLATE is your site template's folder.
There are a few notes about how these files work.
The custom CSS file frontend.css is only loaded if you set the Load custom CSS option in Akeeba Ticket System's Options page to Yes.
Do not try to edit the CSS file directly; it's been
automatically generated by parsing the SCSS files in the
media/com_ats/css folder. We strongly recommend
that you work on the SCSS files in your media override directory and
use an SCSS compiler to convert them to CSS. You can of course
forego our custom CSS completely and create your own
frontend.css file any way you want.
Make sure your file is called frontend.css, not frontend.min.css or anything else.
name, one with the extension .js and one with the extension .min.js.
CannedReply.min.js. Joomla normally loads the
.min.js file. If you set Debug Site to Yes in your site's Global
Configuration it will, however, try to load the .js file instead.
override BOTH files to prevent surprises.
We use Babel to minify our .js files into .min.js. If you don't know how to use Babel it's okay to just copy the .js file with a .min.js extension.
No special handling is necessary. Just make sure that the file name and extension cases matches. That is to say, image.gif, Image.gif and image.GIF are three different files. The files we ship have lowercase names and extensions.