Child Theme without CLI Command

Hey there im trying to figure out how to build a child theme manually without the CLI Command. There is a tutorial for WordPress on getgrav/docs but not for grav.

Please help.

It might be useful.
Theme Inheritance

I hope this guide woll help you:
Once I faced a similar problem when writing for my site articles, which you can see here and this site helped me to answer all my questions.

Thanks for response. I will try that.

Do i need a special PHP version to make php-stream work in my case? I’m using PHP Version 5.6.38

Thanks in advance

Update II
this topic help’d me a lot: Quark theme inheritance

Thanks all