How to dual boot Ubuntu and Windows 10 on separate drives without deleting data already on the drive Ubuntu is going to be installed on?

Question

I have two drives. Drive 1 already has Windows 10 on it and Drive 2 is for personal files and apps. I want to install Ubuntu on Drive 2, but I don't want my existing files on Drive 2 to be deleted. My computer uses UEFI and GPT. How would I go about doing this?