How to fix clock on a 1995 Nissan maxima?

[hjdajklghei]

I have a 1995 Nissan maxima and clock starting going about two years ago, it would work on and off. Now it quit working all together except about once every few months. How do I fix it. Where could I find a replacement clock. Not sure if this matters but the display on the radio quit working most of the time to, and the radio doesn't work 95% of the time because the cd player is broken and always overrides the radio.