Hi,
Easiest thing to do is to swap radios over there if you cannot find a GM export version ofyour radio here, I doubt that your current radio can pick up the european AM/MW and FM bandplan, which you will find out right away over there if it will not. In order to accomodate the different station (channel) spacing over there, you would have to replace the logic section of the PLL for those differences. You might check with a local dealer to see if GM made an export version of the radio for your car, then pick it up here in the US and put it in here, otherwise get the part number and contact a salvage yard over there for that part number.
:I have a buick LeSabre 1998, my original radio is for the USA can I turn it to the system in Europe and how