How do I move modify the origin and orientation of a blueprint in Space Engineers?
Step 1 Use the Info screen to turn on pivot point visibility.
Step 2 Create a new ship of the appropriate class and reshape it until you have a block in the desired position related to the pivot point of the new ship.
Step 3 Use the blueprint/clipboard to create the ship you are trying to change. Position it so it is attached to the desired pivot block from the "ship" in step 2.
Step 4 Remove the extra blocks from the ship in step 2
Step 5 Update your blueprint to have the new pivot point.