Here are the steps to shrink the size of a PDF file:
1. Open the Optimize PDF tool.
2. Select a file to compress.
3. Select "Reduce File Size" in the top menu.
4. Set compatibility and click OK.
5. Rename and save your file.
You can access the Optimize PDF tool from the Tools center in Adobe Acrobat DC. You can also use online services such as Adobe Acrobat online services or TechJunkie to compress your PDF files.
I hope that helps! Let me know if you have any other questions.
