For this tutorial, the local relay chain uses a sample chain specification file with two validator relay chain nodes—Alice and Bob—as authorities. Because a relay chain must have at least one more validator node running than the total number of connected parachain collators, you can only use the chain specification from this tutorial for a local relay chain network with a single parachain. If you wanted to connect two parachains with a single collator each, you would need to run three or more relay chain validator nodes. In general, you would need to modify the chain specification and hard-code additional validators to set up a local test network for two or more parachains.
My question is "How do I modify the chain spec and hardcode an additional relay chain validator to setup a local test network for two or more parachains?"