Xbox 360 To PC (Character Transfer)

Hi all, I was wondering how I make sure that I can get all my 360 characters to the PC. I've had GW1 on PC, Xbox 360 & Xbox1. How do I make sure it goes from 360 to PC & not my old PC account to PC. Also I have transferred my 360 account characters to my Xbox 1 GW2 already, but I was wondering if I could transfer them again to the PC. 

Thanks in advance 

~vSlime