In general all that needs to be done is adding some parameters to the farmer and the node.
subspace-node
Add --rpc-port PORT_NUMBER to the end of parameters.
subspace-farmer
Add --node-rpc-url ws://localhost:PORT_NUMBER to the end of parameters.
PORT_NUMBER needs to be replaced with the port you want to use, for instance 9945.
Though it looks like you are using a community made script so I wouldn’t be able to speak too much to how to change that exactly but I can suggest checking out the docker instructions as its a little more open to modification.