The best way is to download Bitcoin Core and put your bitcoins there, then simply wait for the hardfork to happen.

https://btcgpu.org/

According to this website, you have 21 hours to get your setup ready to access the BGold. You must be holding your private keys ideally, but you can also deposit them in an exchange that will list it, this increases risk tho, with the benefit of having instant access to the coins to dump them. Click on "ecosystem" on that website and you will see the supported exchanges.