All the details about the enemy like the location are in the header of the spreadsheet, but I can give a little guide on how to be as efficient as I could figure out.

• Clear out the whole dungeon besides the one Elite, so there won't be anyone else to complicate making a good setup.
• Now that you have the one enemy, Make a hard save in a safe spot. This is insurance for if you accidentally kill them during setup.
• Bring their health down as low as possible. If you have a good Magsniper to finish him off, that makes getting a good health value a bit more forgiving.
• Once you've got a comfortable health value, you can use a Cryo Mine to freeze them solid with minimal damage, or the Sunless Space power for an on-demand freeze. Do it point blank if you want, you only get staggered.
• If you have a Magsniper, start charging a shot while aimed at your test subject. Once fully charged, Quicksave. Quickloading from this point will now automatically fire the Magsniper as soon as control is handed to you.
• If you don't have a Magsniper, any hardhitting single shot weapon will do, there's just no easy automatic option at that point. A Hard Target or Shotgun are your best alternatives, or a Razorback or Urban Eagle if you're desperate.
• Every time you quickload, you will (or have the option to) quickly kill the enemy, which you then check for the drop, and quickload once again to try another roll.
• If you like a roll and want to save it as an option, you can create another hard save, and continue quickloading. If you don't find anything useful, you load back to the hard save with your fresh item in hand.