The roads around Queensferry can be extremly confusing if you don't know the area, in addition at the time of writing they are improving links to the Forth Road Bridge by upgrading this to a motorway. We therefore highly recommend that you take the B924 off the A90 at the Edinburgh bypass end, follow this under the bridge.

 Park just under the road bridge along the seafront and then follow the footpath taking you under the rail bridge. If you walk along the shore before the bridge, you will come across some rocks which can be a challenge to get past. The path will take you to the shore just past these rocks.