howto update the js_composer in Astra theme

At the begining, a few years ago, a society created the website with Astra theme.

From a couple of months, the modification of pages or articles is not possible because of a problem with the “js_composer” plugin.

So I tried to download a new version.

I pay for that:
“Thanks for buying with us. Below is a summary of your recent purchase. You can download your purchased item at your Downloads page and view your invoice(s) on your statement here.”

After download, that doesn’t work!

I tried to contact the support of “js_composer” plugin.

The answer is:
The issue as mentioned in our first reply is because there is a Visual Composer related code present in your theme added by the theme author. You will have to get rid of it. I would advise you to do so with the help of theme author, otherwise you might loose the extra elements added by him. Once this is done, you can install the standalone plugin and it will work fine.
Unfortunately, this code is added by the theme author via the theme files and hence we are not aware of it’s location. It is for the same reason that we had suggested you to contact him. If we were aware of it or it’s location in the theme, then we would have guided you with a step by step process without having you to contact the theme author.”

I tried to contact the Astra theme author, but no answer is coming…

I tried to replace the js_composer directory in the Astra directory by the new one. But after that I just obtain “error 500”.

Someone know howto update the js_composer in Astra theme?

Thanks for your help!

Jean-Yves