Hi  Vladasyn
I had the same issue (I think?). Your files after you downloaded them wouldn't open? I resolved it by renaming the files so:
02_SONAR_X2_Producer.part1[1] I renamed as 02_SONAR_X2_Producer.part1.exe
02_SONAR_X2_Producer.part2[2] renamed as 02_SONAR_X2_Producer.part2.exe
and so on.
After that, double clicked  the renamed part1.exe then it all went ahead and installed the whole lot.

Yeah, also to clarify, just rename the downloaded files the same names as they are listed on the Download page. There is a .zip or 2 there i think, so you dont wanna name them as a .exe

Vlad, just follow Jean's instructions. I had exactly the same problem.
Jean, thank you. I did as you said and renamed the files using the .exe extention. Everything flowed perfectly from there.
So easy if you know how!!! Thanks again Jean. 

And the winner is answer #10. Thank you very much for posting this. Do not need to remane anything. The installer is located in folder #4.

Now this kind of frustrating. Why in a world Cake would put installer in folder of part 4 and not write about it in instruction? If you are like me, you would open first, folder- no installer, 2nd, 3rd, and give up- I would nevr think to open 4th folder. If it hast to be in folder/part 4, the instruction should be given in the read me file or in the installation instruction. Why even have install. instruction if it does not say where installer is?