How can I modify installed theme

hi, I want to customize installed theme for example
in my case site is installe on
/var/www/test1
I see installed theme on
/var/www/test1/versions/5.73.1/content/themes/source
i try to edit but i think there is a cache doesnt se changes on page, can I manualy clean cache?

how is the best workflow to modify and develop themes?

Welcome to the Ghost community forum, @fpallauta.

Please refer to the following tutorial.

I have closed the other thread; this is the correct category.