Solution
Use the Reduce File Size function.
- From the Document tab, click on the Process
dropdown menu, then Reduce File Size
. 
- In the Reduce File Size dialog, change the options until the Estimated size gets low enough.
- Click OK.
Note: Many of the options in the dialog will also affect the clarity of your document, so it’s a good idea to perform this operation on a copy of the file, rather than the original.
If you want to reduce the file size of a large number of documents at the same time, you can use Batch Reduce File Size.
- On the File menu, hover over Batch, then click Reduce File Size.
- In the Reduce File Size dialog, choose the options you want and add the files to process.
- Click OK.