The sentence isn't grammatically correct, but, "some habits however, were to change" means; Habit = something you do a lot, and in the same order, at the same time, for the same reason, say for an example, every time you talk on the telephone, you draw little patterns on some note paper, that's a habit; every time you have a cup of coffee, you want a cigarette, that's a habit. Change = to make different. Some habits (not all) were to change, just means something you do as a habit would have to stop or be altered for some reason.

It is hard to change habits. A habit is something you do without thinking. Either your body is addicted to the activity, or the behavior is ingrained in your brain and it would take great effort to change the pattern. An activity can change with great effort, and you can create new ways of doing things. This vocabulary above may be incorrectly translated, and perhaps a different word should have been used instead of "habit".

There is a saying in the States, "some habits never change" meaning some people have habits or ways of living that they will never change either because they are too set in their ways or they don't want to.