Since this seems to have become an expanding project and several hundred people have already subscribed, I am including these instructions for those who have already begun a survival world but would like to see the new features without starting their whole save over fresh. Read through to the warnings at the bottom before you do anything!

• First, you will need to enable the /tse command for Real Solar Systems. This is disabled by default to prevent people from wrecking the save by tinkering with things they might not understand.
  
  • Navigate to and open this file in a text editor:
    "C:\Users\{Your User Name}\AppData\Roaming\SpaceEngineers\Saves\{Your Steam ID}\Proper Solar System with Asteroid Belt, Trojans (Real Solar Systems World)\Storage\3351055036.sbm_RealSolarSystems\ConfigSettings.xml"
    
    
  • In line 3,
    <EditorAllowed>false</EditorAllowed>
    , change the "false" to "true". Save the file. You might want to leave it open to easily restore it after you're finished.
• Run Space Engineers and start your saved game. Wait until the lighting changes happen, so that RSS is fully loaded and working properly.
  
  
• In chat, type
  /tse
  to start the RSS in-game editor.
  
  
• Use the Insert and/or Delete keys to navigate to the planet/asteroid you wish to change.
  
  
• Use the PgUp/PgDn keys to navigate to "Planet Type" on the upper right "Main Options" panel. Press Home to select it.
  
  
• Use the PgUp/PgDn keys to navigate to the new Planet Type. Press Home to select it. There may be a brief pause as the game changes the body.
  
  
• If the body you are changing is a named asteroid, use PgUp/PgDn to nagivate to the Orbit Zone Radius. Press Enter and type "50", then press Enter again to accept the change. Do the same for Surface Zone Radius. This is done to change the way the proxy works, in order to make the transition between proxy and voxel less apparent, since proxies can only support round worlds properly.
  
  
• Use the PgUp/PgDn keys to navigate to "Edit Heirarchy" and press Home to select it.
  
  
• Use the PgUp/PgDn keys to navigate down to "Recreate Planet" and press Home to select it.
  
  
• Answer the "Respawn [PlanetName] voxel planet?" with the appropriate response (usually "[" to accept or "]" to cancel, but this may vary by keyboard layout and language/locality.

Performing the above actions will recreate the voxel mesh of the planet/asteroid in question. It will be recreated in a completely new location. ANY AND ALL GRIDS ON SAID PLANET WILL BE LEFT FLOATING IN SPACE IMMEDIATELY, as the planet below them vanishes. Any GPS locations associated with the planet will remain but will be invalid, and the GPS location listed in the Discussions section will be invalid as well. Certain spawn options using the respawn mods (namely those of Io and Mars) will no longer function if the planet is regenerated, although the option will remain onscreen. The pod will spawn in empty space near-ish to the map origin.

You do not need to delete any world in order to recreate it. If you do delete it, you would have to re-enter all of the planet's statistics in order to restore it. That is a pain in the ass. I would highly recommend not doing that.

If you recreate Earth or Mars, they will be recreated in random locations depending on the current RSS settings. Since they are the most likely spawn and gameplay locations, I have manually placed these two worlds as close as possible to the map origin in order to minimize floating point math errors and avoid certain anomalous RSS proxy gravity issues during save loading. Recreating them in random locations will not break the game, but you may see static grid hitboxes that do not fit properly or you may even see unintended, unreachable static planets appear in the sky. If you are familiar with SE Toolbox, the planets could be returned to their original locations using the coordinates listed in the pinned GPS Coordinates discussion.