This is a simple python script that will read exported object files in SpaceEngine and let you replace any object with another. You can add any object by exporting the object file in SE and adding it to the "objects" folder.
Right-Click on SpaceEngine in Steam and go to Manage > Browse Local Files
Open the addons folder and create a new folder inside called "catalogs" (EVERYTHING IS CASE SENSITIVE)
Now open the catalogs folder and create a folder inside called "planets"
Open SEReplacer.exe and set the output folder to the planets folder you just created.
Make sure you don't move the .exe out of the folder and do not delete the objects folder.
The "Target" is the object you're replacing. The "Replacer" is what you're replacing that object with.
After selecting what you'd like click "Generate Script"
Start or restart SpaceEngine.
You will have replaced the object of your choice.
To return the game back to normal simply click "Return game to default"
You can't replace multiple objects at a time. If you try to replace another object the program returns the game to default first.
You can add your own objects to be targets or replacers by finding an object in SpaceEngine and clicking shift+f2, then click export, then put the exported file (located at Steam\steamapps\common\SpaceEngine\export) into the objects folder.
There seems to be some bugs when trying to replace the Sun. It likes to delete the whole solar system. A way to get around this is to edit MySystem.sc (located in Steam\steamapps\common\SpaceEngine\addons\catalogs\planets) and delete the line that says "Remove "Sun" { ParentBody "Solar System" }" but this means the sun will still be there so the object you're replacing it with has to be bigger than the sun to be visible.
Feel free to change or distribute this program.
SE Replacer Created by @SpaceChip on Discord