only 2 ways. donate them or deposit into branch/coin deposit machine for bank account or to pay credit card bill. of cos don't go there with just a single piece of 1c. accumulate alr then go. otherwise donating will be wise, usually charities knows what to do with these 1c. 1c are still legal tender, but just no longer in circulation
i closed my uob account with 1c inside 2 mths ago and counter wanted to give me 1c i asked them i can't do anything with this. she then suggest me that she can use it to pay to credit card bill offset.