How to fork a cryptocurrency I have cloned a coin and changed some variable to make it my own coin. I have launched it and have a few mining pools mining my coin. Going through the code I notice I have an error and the reward halving starts over at block 10k. So miners are getting 500 coins per block instead of 250 coins. I believe this sort of change would fork the coin to a new blockchain but I want current holders to keep the same amount of coins on the new fork. How can I change the code and fork the chain to comply with the new info?

https://github.com/DataSaverCoin/DSC/blob/master/src/main.cpp
Compile the code. Release the new client. Old and new version will disagree at some point in the future (block 10k in your case) et voila, you will have a forked chain.