Open the console with `~`
Type `ent_remove`
Look at the entity you want to delete
Click or press `E` if needed to target it
If you want to remove all entities of a type, use `ent_remove_all
If you want to remove a specific spawned prop, point at it and use the remover tool
If you are an admin, use the Admin Cleanup tool
If you want to delete your own spawned prop, use the Physgun or Toolgun remover
If the entity is stuck, use `kill` on it if supported by the server or addon