Change Frequenze Band from US to European

I bought the Jensen for my car in Europe, but the Radiofrequence here works in smaler steps.
None of the shops here is familiar with a Jensen Radio.
It's a great radio and I would like to hear all the rradio stations.
So maybe somone here can tell me how to change the radiofrequence from US to Europe style.

It would be great

Thank's FRANK