Thank you! Unfortunately I'm not able to edit objects that are contained in an already existing .kn5 file, I only know how to add more objects by adding more .kn5 files in the mod folder. However it's not impossible, but you need to convert the .kn5 file into a 3d model, then edit and export it again using ksEditor. The only problem is to reassign all the textures that are contained in the track and I don't have the right skills to do that.