Hi...
I`m Peter, an experienced audio-freelancer. I did similar audio works in the past .
as I checked your attached mp3 .. because you have only mp3 as source -to create backing track from it, it `ll need to write down=note entire song as sheets /with harmony, melody, rhythmical structure, flow and changes/ all that "by my ear-only", then I can go to create arrangement based on those written from audio, then add right instruments, mix it all right (levels, effects,++) then record, and master,
if you want to have it done right with top quality-it 'll need few days of my hard work to complete project
it must go this way, having your mp3 as only 1 source for so not simple audio,
..but I can do it for you
..let`s chat about it.. and let start once all is cleared..
rgds
peter