There is nothing you need to do in case of a hard fork. Just make sure that you control the address that you are holding the bitcoins in instead of having on a shitty exchange like Yobit who is generally very unclear on their policies on altcoin hard forks.

Once a fork happens you’ll have both BTU and BTC coins 1:1, the process is automatic.

If you think that bitcoin is doomed because of this fork, sell your coins now, and buy them back later when it is probably going to be cheaper.