xml file splitting conundrum (mac)

I’m trying to import a WP xml file into a new weblog. It’s about twice the allowed size, so I’ve been reading through the forum’s many threads on how to split xml files into chunks that are importable.

From posts that are two years old (here) I extracted and tried a python terminal command approach which doesn’t work for me (and it’s probably my fault). This is the result (0items when the xlm file is 19.3mb):

rosinas-MacBook-Pro:Desktop rosina$ python splitter.py wordpress7Aug13.xml 

File "wordpress7Aug13.xml" contains 0 items
Creating 2 files with at most 0 items each:
   Writing chunk 1 to file wordpress7Aug13_1.xml...
Done!

I’ve seen a mac program mentioned in a couple places, but that leads to a dead end.

So unless I’ve overlooked something obvious, I am stuck. Any advice would be greatly appreciated. Or, if somebody has used the Windows utility that takes care of this problem and would be willing to split my xml file for me, that would also be tremendously helpful.

Thanks for whatever insight and help y’all can provide.

Edited to add: I have tried to use the advanced export utility which would allow me to export smaller chunks, but oddly enough it gives me a “You don’t have permissions to use this page.” message. I have uninstalled and reinstalled the export utility, but I still get that same message.