This is a little more difficult in HM2 because you are suspicious carrying a sniper rifle in any disguise. Therefore, the only place I found you could do this, without raising suspicion and ultimately combat, was from the Ruins. Use the ruins at the starting location with the jaeger 7 Lancer hidden in ruin. The principle is still the same hit the bells in order; (1) halfway up left most mast, (2) on very front of ship, (3) at the top of the right mast, and (4) at the front of the cabin. (P.S. yes, I suck at aiming)
Video links:
https://m.youtube.com/watch?v=rOSihf5feh8&feature=y....behttps://www.facebook.com/dubear.doppelganger/videos/21875752...**I also go slow as I was on the lookout for guards the whole time because on professional they alerted 1st shot in every other location, I tried. Fortunately, no worries from this location.