how can I print just a part of the page and not the full page with Adobe Reader v 10.1.2?

Two ways to print a portion of a page: zooming or using the Snapshot Tool.

ZOOMING:

1. Zoom into the area you want to print.
2. Click the Print icon.
3. Under "Pages to Print", make sure "Current view" is selected under "More options" (you may need to click "More options" to open it).
4. If you aren't satisfied with the preview, try clicking "Fit" under the Size button.

SNAPSHOT

1. Choose Edit > Take A Snapshot.
2. Drag a rectangle around the area you want to print. 
3. Click the Print icon.
4. Under "Pages to Print", make sure that "Selected Graphic" is selected under "More options".
5. To enlarge the snapshot to fit the sheet of paper, choose "Fit" under the Size button.

Hope this helps!

I don't think you can do that with Adobe Reader.

What I would do if I needed the same is convert the PDF to another format (Word doc or image; search Google for a free conversion tool), then eliminate the information I don't want.