Make sure to NOT pronounce the "h".
Make sure that the dipthong "ch" is gutteral.
Each word has a separate audio link:
LISTEN -> Frohe Weihnachten
Here are other common greetings during the holiday season:
Fröhliche Weihnachten - Merry Christmas!
Frohes neues Jahr - Happy New Year!
Alles Gute zum neuen Jahr - All the best for the New Year!