I partitioned the HD of MBP896 to 2 partitions, one for Mac, the other one for PC... But now, I want to repartition the HD to free up some space for Mac . But problem is, how can I make it without erasing data on the PC partition.....
This cannot be done. The only way for you to free up space for your mac partition would be to use boot camp utility and delete the pc partition. Since it doesn't sound like you want to do this, you are out of luck.