People seem to hate answers without conclusivity, but I think this is a case where uncertainty is the answer. Japanese, like all languages, is in flux. As such, there are cases where there is not yet overwhelming consensus on ways of expressing certain ideas, and I believe that this is one of those cases.
Consider in English that there is controversy about whether "microphone" should be abbreviated to "mike" or "mic". I personally stand by "mike", but there are a lot of people who insist it must be "mic". Similarly, people are still in flux about whether electronic mail should be written "email", "e-mail", or if simply "mail" is sufficient.
For a Japanese example of a word in flux, there is the matter of the reading of
雰囲気. The kanji should, according to most dictionaries, be read
ふんいき, but most people I know say
I've never before considered which is the kanji for
かえる in the context of a television before, but
変える are both correct enough as far as I can tell from looking into it a bit. So go with the one you prefer, and be prepared that you have a 50/50 chance that the one you're using could fall out of favour in the overall Japanese speaking world. As an interesting side note, as television slowly loses relevance to consuming entertainment over the internet, it may never really come to a solid resolution, as it might become too unimportant to really finalize.
As a native English speaker, I can make a personal insistence on "mike" for "microphone", and I go with "email" and sometimes just "mail" depending on context. I don't care how much anyone else claims to know the language, I can make my case for how I speak and stand by it. As a non-native learner of Japanese, the reality is that it's much harder to participate in the language that way. Especially in consideration of a strong cultural thread in Japan that has many Japanese people believing that the Japanese language can not be truly understood by non-Japanese. You may very well encounter Japanese people who will insist that one or the other kanji is the definitively correct one, and they will not allow for you to be making a choice of your own. There is also a strong perception among many Japanese that there is little subjectivity in their language, and their sense of consensus necessarily means for them that their individual take is de facto objectively correct. Not all Japanese people, of course, but when dealing with such people, in the course of their interaction with you, they will not consider the existence of other native Japanese speakers who might disagree with them. That's just the reality you have to contend with sometimes. If you want to stand by your choice, you'll have to back it up with more evidence than you might if you were speaking your own native language.
So, the bottom line is both
変える are acceptable enough... for the time being. I personally like
替える. Which do you prefer?