This transaction (e8c5...) will never confirm because its inputs have already been spent by transaction 93cc4fe50e6069dccb827f56636bb4cd20f9865dd4d7e3b7946bbbca97576e80, which currently has 9 confirmations.

There isn't any inherent need to cancel transaction e8c5; the network is never going to consider it valid. You might want to remove it from your wallet client software in order to avoid having it display an incorrect balance or other confusion. How to do that will depend on what software you are using.