You’ll get this side quest by talking to Danny Clarkson in Episode 2. Danny’s Location: You can find him on the east side of Clarkson Cold Storage Building [TIP: to know the exact location of a NPC, fully zoom the map. The map will start displaying the NPCs as ‘Blue dots with name’].
Where to find the Memory of Galena
Go to the CLARKSONS’ MANSION (Daniel’s House) on the extreme North -West corner of the map. Go to the swimming pool (behind the mansion), kill the alligator & take the precious Ring (memory of Galena).
Return Galena's Ring to Daniel
Danny will be drinking in the Owl’s Nest. If you can’t find him there just use the map to locate Dany and return him the ring.