"That is not going to be easy to organize."
Translation:Ça ne va pas être facile à organiser.
There is no reason to replace "ça" with "ce". If you want to use literary French you could replace "ça" with "cela".
"ce" is mostly used to designate which thing exactly we're talking about. "ça" or "cela" are mostly used as substitutes for nouns we already talked about earlier in the discussion.
- "Ce chapeau est à moi." = "This hat is mine." (this specific hat, not any other)
- "Ne joue pas avec le feu, ça brûle." = "Don't play with fire, it burns." (here "ça" replace "le feu", because we're not going to repeat it. It works the same way from a sentence to the next.)
I have heard people try to give rules for when a verb uses à and when it uses de. After all is said, I don't think there are one or two rules that will tell you when to use one or the other. Lawless gives instruction on this and it is worth a look.
Sorry but that isn't a good explanation, you've contrasted using ce as an adjective with its use as a pronoun - see Satspy's answer below for a more accurate account, also http://french.about.com/od/grammar/a/indefinite-demonstrative-pronoun.htm
Unfortunately Satspy's comment is not accurate either. You can use "ce" as a pronoun with other verbs than "être" such as "devoir" for example.
It's true however that I forgot to mention that "ce" can be used as a pronoun as well, probably because it's not really used in common French anymore, except for its short form "c' ". For many expressions, we use "ça" instead.
There are still expressions where both are acceptable in common French: "Ce serait bien." and "Ça serait bien." are both common French.
As for this exercise, it doesn't change anything, you can't use "ce". "cela" is the only alternative if you want to use formal French.
But the article you provided surely explains this matter a lot better than I do.
I originally typed "ça ne va pas etre facile a organiser" and it didn't take it, saying i need to use "sera" instead of "va". So on the second go, I used sera and it worked, but here in the discussion area, the translation is identified as what I put originally. Should I report this?