How do you replace and where do you find replacement rubber for shower surrounds?

I don't mean for the door, but the rest of the shower. My rubber is loose and I don't know how to replace it or where to find the rubber to hold the glass in.

Please advise.

Thanks,

There Are Shower Door Companys Or Glass Companys Im Sure Where You Live, Id Try Them

Why Not Thouroughly Clean The Surface And Buy Some Silicone With A Matching Color And Silicone The Cracks And Seams.

Not so sure the silicone is what she needs. These are soft rubber sweeps that seal. They are replacable but no normally a hardware store item. Glavines suggestion is a good start.