Yes, it's possible:
- Display the Protect Document Task Pane.
- Check the box "2. Editing restrictions" for "Allow only this type of
editing". The dropdown becomes active, and you can leave "No changes" or
select one of the other types as needed. The entire document becomes
protected with the type you chose.
- Select an area of the document that you want to allow to be edited (that
is, where you want to remove the protection). Check the Everyone item under
"Exceptions", or supply names of specific individuals who can edit. Repeat
this step as many times as needed to unprotect parts of the document, until
only the desired areas remain protected.
- Then click the "Yes, start enforcing protection" button. Supply a password
if you want.