"Kill security guards" is a mission objective in the story mission "An Urgent Message" in Borderlands: The Pre-Sequel
Walkthrough
Head into Harren Lockup. You need to clear the area of the Lost Legion in it. You have a good number of Lost Legion Marines, with the odd Lost Legion Sergeant, Scout or Medic. You will need to cover the whole of the area to find all of them
An Urgent Message Mission Objectives
- Access security office
- Kill security guards
- Talk to Nakayama
- Access terminal
- Shoot terminal
- Defend Nakayama
- Upload message
Turn in: Professor Nakayama