Had the same issue with a Chevy Lumina APV and found an answer.. Turns out to be way easier than you might suspect..
AutoZone.com | Funnel
Check out part number 10704 on this page.
And 10106B-6 on this page
AutoZone.com | Oil Spout
I linked to Auto Zone on both items.. The last one (Hipkins/Trans fluid and Gear oil Spout) is what I used to add brake fluid to my Lumina.. I just screwed it onto the top of a can of brake fluid and ran it in. If you need to any hardware can sell you a longer plastic tube for added reach.