Changeman actually HAS been subbed fully (Barring one episode, for some reason) by some group known only as "DFF". They seem to be long gone, but if you look hard enough, you can find them online. It's a good show that I recommend checking out.
DFF is Dead Fish Fansubs. It was long defunct even when I got into toku, but was still being spoken of back in 2010. Apparently it was one guy subbing by himself. For some reason instead of subbing shows in order he would do what he considered to be the most important episodes of a series first, and then fill in the gaps. I don't think he ever actually finished a show entirely, though as you say he got closest with Changeman (I believe episodes 21 and 25 and the first of the two movies were left unsubbed). He also did something like two thirds to three quarters of Metalder, and a small number of episodes of various other shows.
Changeman is being re-done by GUIS. It may be easier to wait for them, as torrents of Dead Fish's subs tend to be difficult to find and short-lived, and the DLL links were killed when Megaupload was brought down.
I'd also recommend that people get any of the Gao Soul Forever subs that may interest them (Gaoranger, Sun Vulcan, various 'Vs Series' entries and both seasons of Ecogainder) sooner rather than later. Their website died a while ago and while the torrents are still out there these things have a habit of gradually fading away.
