I did it on my previous 75, it was fairly straight forward,
and if you search on here I recollect a post from Greeners with details of his installation. All I did was to cut and extend the loom for the cd player, and then route the cable down the driverside sill
I cobbled up some brackets out of old radio brackets in the tool box, and cut the trim to fit around it.
On the present 75 I have replaced the cd changer with a Grom unit and now use that to play all my music from my phone.
HTH Neil