http://download.cnet.com/PrimoPDF/3001-18497_4-10264577.html?part=dl-10264577&idl=n&spi=2ca4162015b9be5faa267caa4efa2673
Download freeware PrimPDF from the link above. Install then follow the instructions below. The idea is to redo the PDF file and save in a smaller size.
1. Open the target PDF file.
2. Open the Print dialog.
3. Select PrimoPDF from the list of printers.
4. On the PrimoPDF dialog, click eBooks. (or select Custom to down size manullaty in your case. You can do a few trials then pick the best to suit).
5. Click OK.