alrite mate its easy enough if not seriously time consumin!
first off its much easier if you remove the top half of the dashboard...the DC-DC convertor will be seriously hard to position so its not in the way if u dont...if u dont know how to remove the dashboard follow the tutorial on cliosport but dont forget to pull off the A-pillar trims at the end otherwise itll never cum off...
right once its off get some 27amp cable from halfords and connect to the battery...if u look under the right hand suspension turret in the engine bay theres a huge grommit that the bonnet pop cable runs through...put a hole in it and run the cable through...then cums out behind top left hand side of dashboard...fit the cage from the stereo and then start pluggin in the ISO blocks...then solder the positive cable to the one uve just run and heat shrink it. once thats done look for a small bolt at the top of the dash just behind the original stereos display at the top of the screen...if u route the cable carefully it will reach this bolt without extending it...should already be two wires earthed to that point...once thats done, plug the loom into the back of the alpine. start slidin it in while positionin all the pre-outs + DC-DC convertor to the left hand side of the unit in the space between the glovebox and the stereo,
re-fit dash, job done! any probs, PM me