You just need to use the auto-installer. I chose a dummy folder, then moved the files into my FSX folder by hand.
The additionnal steps, that are described in the readme files, are just made to enhance the visual further, and there are english-written files too

I haven't done these modifications... I have just moved the St Bath TFFJ folder in my addon scenery folder and declared it in my scenery library (because the program had not done it, if I remember correctly...).