Nothing wrong with a four track recorder for simple audio - somewhere in the gadget trunk I have a neat Fostex 4track and even a Tascam reel-to-ree.

Okay suggestion for next time. Open the video in simple editing program like Video Studio timeline.

Then import the sound as a wav file and drop that file into an audio timeline.

It is pretty easy to drag the audio around until it synches up to the beginning of the video track. I've done this about a zillion times and it's easy to do.

Once sound synched with video just render out as whatever file type and size for your upload.