before you swap the files, make a backup copy of the folder
after that you only need to add the three textures to the folder and overwrite them.
eg. in C: \ Farming Simulator 2019 \ data \ objects \ roundbales
Take no guarantee for damage.
Credits:
XaaD
youre showing the flat side of straw bales as old texture and in new textures part you got 4 of the identical thumbnails which are of grass bales it seems ?