Convert GoogleMap API v2 to v3

I have a php script with javascript and html using some routines from GoogleMap API examples and need to get it converted from v2 to v3. The script I am using loads a txt file and then generates a map with markers. It uses GDownloadUrl, which presumably needs to be replaced with the appropriate jQuery call. I'd like to get it well organized with link to local javascript files so I can easily re-use on other websites. One of my sites is broken, which I am pretty confident is due to the v2 deprecation. I am attaching the code from one of my websites that uses the code and in this case with just a handful of points to debug. Once it works on this site I will fund milestone 1. I will then migrate the code to other sites. Once the code works for those sites I will fund milestone 2. The other sites use virtually the same code but includes much larger data files including points throughout the globe. Ideal candidate has worked with GoogleMap api v2, GoogleMap api v3, jQuery, PHP.