Only 2 of those items are in dungeons that you can queue for in the dungeon finder:
Blade of Eternal Darkness is from
Princess Theradras, the final boss in Maraudon. I believe you queue for Maraudon - Earth Song Falls
Book of the Dead is from
Balnazzar, the final boss in Stratholme. Queue for Stratholme - Main Gate
The other two, you will have to enter the dungeons through the main entrance.
Circle of Flame is in Blackrock Depths. Probably the quickest boss to get to, but can be difficult since he gets stronger the longer the fight lasts. Use the tunneler at the entrance, pick "Just past the Grim Guzzler," take out the first group of mobs that are in front of you, go through the corridor that between the 2 groups of mobs, that corridor will make a 90-degree right turn and it will put you in the room with
Ambassador Flamelash, who drops the helm.
Embrace of the Wind Serpent is in the Sunken Temple aka Temple of Atal'Hakkar. This is another easy boss to get to and an easier boss to beat, IMO, than Ambassador Flamelash. Go through the entrance corridor to the first mob group, kill them, turn right, go to that second group of mobs, kill them, turn right again, go down that corridor, kill that wind serpent in the middle of the corridor, avoid the other 2, the corridor will head left to a room with 2 wind serpents and a skull pile, kill the 2 wind serpents, click on the skull pile to summon the
Avatar of Hakkar, who drops the chestpiece.
IMO, Discipline makes it easiest to solo dungeons. Also, make sure you are in the present timeline in Chromie Time or else these bosses will be much harder. If you're having a hard time soloing these bosses, you can use the dungeon finder to get "the trinkets."
Shadowgrasp Totem is dropped from
Mueh'zala in De Other Side
Infinitely Divisible Ooze is dropped from
Margrave Stradama in Plaguefall
Either of those trinkets will make it really easy to take down bosses. Have Chromie put you in the Shadowlands timeline to queue for those dungeons in the dungeon finder.
