For example, I want to deploy a contract to my local testnet. But I only have its opcode from etherscan. How to deploy the contract with just those runtime bytecode?
You will also need ABI, not just bytecode. Look at the next article, it will give you good starting point: https://medium.com/@prashantprabhakarsingh/deploying-contract-using-bytecode-myetherwallet-and-remix-10f643a82d40