I hate to say this, but he doesn't even detail their level of intelligence. There very well could be life around Venus in the atmosphere for instance: https://www.nature.com/articles/d41586-020-03258-5 How intelligent are they? What is their physiology? If they are in fact tiny insects or microscopic, then a subterranean base on Mars would be trivial. Our participation could simply be logistic in nature. Nothing was said in detail. If we can make 7nm bitcoin miner ASICs we could certainly do that. He's being very intentionally non-specific for a reason here. Like it's a less-than spectacular life-form? With less than spectacular space travel?