How change the memory size in PCIe Hard IP in Qsys

I have successfully generated the Altera cyclon4GX PCIe gen1 x4 HardIP example using PCIe compiler in Qsys with on chip memory and DMA using Quartus 11.

Pci express core contains the following BARs

(1) BAR0 - Contains 27 bit (auto) prefetchable memory that can support upto 128MByte of memory

(2) BAR2 - Contains 27 bit (auto) non-prefetchable memory that can support upto 128KByte of memory.

I would like to change the BAR0 and BAR2 to support much lower size may be 128MBytes of memory. I am not sure how to change this value ?