Who do I have to kill and where? Doable via group/raid only or soloable?

Outside the entrance to Blackrock Spire there is a hallway with some mobs. Follow it to the end and kill the Scarshield Quartermaster (level 54 or so Elite - easily soloable at 60, though you might want some help with the other mobs there). He drops a quest item (both in a group and a raid). Right click it to get the quest.

Enter UBRS with a standard Raid and kill Drak - click the orb behind his spawn and you are now attuned for BWL. You don't have to be present for the Drak kill - just click the orb behind his spawn. When BWL was new, many guilds would run UBRS, then summon people up for attunement.

To zone into BWL - click the Orb in the Quartermaster's room outside BRS.

Awesome, thanks for the help. I probably will never need it but figured what the heck its a good thing to get:)