I have follow this quick start howto:
https://docs.pagure.org/copr.copr/user_documentation.html#quick-start

and i have correctly upload and rebuild my src.rpm package on copr.

Now I must modify a source file and .spec file then rebuild the package.

What is the best way to procede?

I must modify this files in local, rebuild src.rpm in local then re-publishing it to copr, or I can modify these files on copr?

Let's me know.

Many thanks
-- 
Dario Lesca
(inviato dal mio Linux Fedora 31 Workstation)