Escuse my bad English I will try to explain you that what u want is impossible to do
You could find someone that could separate songz about their frequences but it always have and create parasite noise. Depends on the format recorded that u will give to the guy who will try to do it.
I know it cause in rap we use sampling and this is one of the base that u must learn before u sample anything
The best solution would be to use what u found yourself in a best quality...
I had this problem many times in my life and it s impossible to solve it properly.
Another thing would be to find the original samples from the song. If had been sample of course. And use them.
Check this website
https://www.whosampled.com/Best regards