I presume you want the name of the file to be presentation.doc (i.e.,
just one .doc, not two)?
I assume you are on a Windows machine?
Do you know how to use Windows Explorer? Bring up Windows Explorer, and
navigate to the folder where presentation.doc.doc is stored. Click on
presentation.doc.doc to select this file. Press the F2 key (the F2 key
is the "rename" function). After you press F2, a black box should
appear around the file name and you'll see a cursor inside the box at
the end of the file name. Just type in the name you want, in this case
"presentation.doc"
