UART FIFO

Hi,
i got a problem with the UARTn FIFO .
Can someone explain me how i get the data from this register?
The manual says that, if i enable the Rx trigger level
for example level3 (8 character) the RxFIFO get the data and after the 8th char is arrived interrupt is set.that works so far.
but where are the data?

thx