I think the solution is a lot more easier. You only need to use the function the_content() instead of the_excerpt and you’ll be able to change the […] for a “Read more…” or whatever text you’ll choose.
The solution is explained in the official Docs from WordPress:
Detailed explanation on how to use the_content()
I was able to easily change the […] by a “Read more…” adding the quicktag <!–more–> to the html post and replacing the function the_excerpt() by the_content(‘Read more…’);
There’s a second solution exaplained in the official Docs from WordPress that uses filters to replace the text […] in the_excerpt() by a string you define, find the link below:
the_excerpt() vs. the_content()
Hope it helps.