This pathway is a bit hard to find, you should do it at daytime not nighttime. The bottom of the path is between 33 and 34 Marine Parade, the top is between 49 and 51 Marion St. There is no place to park or turn a car on Marine Parade so walking is best. At Marion St, the pavement goes across driveways so it would be hard to find the top of the pathway at night. You are looking for a 50 ml pill bottle at ground level.
Only the path going between Marion St and Marine Parade is public, the side path is private so don't go down there.