-Give him the Militech's chip.
-Shoot him in the head directly "Bam...!" (what i always do).
-Pay him with your own money.
If you give him the chip (the chip is lost):
-If you have hacked the chip and remove the malware : Royce is happy and Militech not (you have to fight Militech).
-If you haven't hacked the shard or "just" not removed the malware (you can "copy the malware", "remove it" or both if you can) : Royce is not happy at all, and you must fight him before leaving the factory (in his mech suit). Militech is happy and later you receive a quest from Meredith (Venus in Fur).
With those details, normally, you could remember your choice