Probably not necessary; if you really feel that the chassidish practice speaks more to you and you want to switch, talk to a rabbi.
Some of this will involve whether you believe the old customs or new ones are more accurate, by the way.
Look, 500 years ago, each place had its own customs, and when you moved to a new place you generally picked up the practice of the local population. So if everyone in Frankfurt did this 200 years ago, and your great-grandfather permanently moved there from Galicia, he would be expected to say "now I'm a Frankfurt Jew" and switch over to Frankfurt customs. And that's fine. Things have gotten more interesting recently, as people move around more often and things are more multicultural.
Rabbi Moshe Feinstein's father converted from chassidish to generic Volozhin "Litvish" yeshivish (that was one of the terms of a shidduch suggested to him with a very respectable young lady!), which his son basically upheld. (Okay his father even skipped "Barchuni leShalom" every Friday night, Rav Moshe didn't go quite that far.)
Similarly, Rav Moshe wasn't so warm-and-fuzzy about ancestral Ashkenazim davening nusach Sefard, and he allowed any Chassidish fellow who so chose to switch his siddur to generic Ashkenaz if he wanted to. Rav Moshe felt that nusach Ashkenaz was our tradition as we received it -- yes it may have evolved, but unlike nusach Sefard we have no indication that some actively/intentionally made changes to the siddur. So I'd assume the same would apply to a minhag Ashkenaz siddur.