2) Under Filters, click ?Add?
3) Double-click the new filter and rename it compressed
4) Click on the Details button
a. Set the Color pull-down to Images
b. Set the second pull-down to Compression
c. Set the third pull-down to JPEG
5) Select a Quality setting
6) Click the Apply button
7) Do a Save As under a different file name
Check the file size of the new file against the size of the old file. Depending on the number of images within your PDF, the size of the file should be considerably smaller.