Looks like a pretty standard Shimano style cartridge bottom bracket. You will need a tool to tighten it into the BB, can't tell what type from the City Grounds website as they only show the BB edge on, but I would guess it's this:
Park Tool Co. » BBT-22 : Bottom Bracket Tool : Bottom Bracket
Does this video help?
https://www.youtube.com/watch?v=_Kf-V5iulaU