Thanks a lot to HCP for the detailed illustrated instructions, that helped a lot and I got all my BTG's. I exchanged them for BTC on Coinomi, thru Changelly exchange: there was quite some waiting time for the exchange to complete, but all is well now.

Thks a lot HCP for the clear summary, I did it for a single wallet and it worked perfectly.
This is the link I used for the clean electron cash wallet: https://electroncash.org/