You have already been given the best advice by Brad Martin. The courts are quite unforgiving of any change, however slight, in the format of their forms and I would not trust any "import to edit" function of MS-Word. The danger there is you could end up editing the form itself rather than just filling in the fields and one never knows just how perfectly the "import to edit" function will work. I've currently got Office 2010 on this machine and no easy access to Office 2013 so can't do a quick test to see for myself.
Since you entitled this thread "fillable PDF forms" that gives me the impression that this one has already been opened at some point in Adobe Reader or Adobe DC and you've received the announcement that it is a fillable pdf that allows you to save the data when you're finished.
Simply download and save the file, open it in Adobe Reader and do your filling-in there. As already noted, if the form doesn't allow itself to be saved once filled out you should simply print several copies when you're done entering your information. If push comes to shove and you need to file it electronically, just scan in the filled-in and printed form.
You really want to have these sorts of materials in precisely the format issued by the court.