The changes occurred both in the old Jewish scriptures as well as in the New Testament scripture. The changes consisted mainly of important passages being omitted form it, rather than words changed to read differently. The Old Testament in particular makes references to many books that have been omitted from it, and is no longer found in the scriptural canon. There is plenty of evidence for that.
He didn’t need to. See above.
zerinus
Samaritan Pentateuch - On the return from the Exile, the Jews refused the Samaritans participation with them in the worship at Jerusalem, and the latter separated from all fellowship with them, and built a temple for themselves on Mount Gerizim. This temple was razed to the ground more than one hundred years B.C. Then a system of worship was instituted similar to that of the temple at Jerusalem. It was founded on the Law, copies of which had been multiplied in Israel as well as in Judah. Thus the Pentateuch was preserved among the Samaritans, although they never called it by this name, but always “the Law,” which they read as one book. The division into five books, as we now have it, however, was adopted by the Samaritans, as it was by the Jews, in all their priests’ copies of “the Law,” for the sake of convenience. This was the only portion of the Old Testament which was accepted by the Samaritans as of divine authority.
The form of the letters in the manuscript copies of the Samaritan Pentateuch is different from that of the Hebrew copies, and is probably the same as that which was in general use before the Captivity. There are other peculiarities in the writing which need not here be specified.
There are important differences between the Hebrew and the Samaritan copies of the Pentateuch in the readings of many sentences. In about two thousand instances in which the Samaritan and the Jewish texts differ, the LXX. agrees with the former. The New Testament also, when quoting from the Old Testament, agrees as a rule with the Samaritan text, where that differs from the Jewish. Thus Ex. 12:40 in the Samaritan reads, “Now the sojourning of the children of Israel and of their fathers which they had dwelt in the land of Canaan and in Egypt was four hundred and thirty years” (comp. Gal. 3:17). It may be noted that the LXX. has the same reading of this text
htmlbible.com/kjv30/easton/east3203.htm
Samaritans. While not frequently cited in New Testament texts, the Samaritans are a good example of division amongst the Jews of Jesus’ era. The parable of the “Good” Samaritan is often seen as highlighting the prejudice of the time which held that Samaritans were inherently “bad,” or at least inferior to the supposedly purer Jews of Judea.
The third group, the Essenes,This group is also referred to as the Qumran community; they are generally believed to be the authors of the Dead Sea Scrolls
Essenes did not marry; they shared property in common; they ate all meals together; and they lived a strictly regulated life of study and prayer; and they held themselves to a higher standard of virtue than others outside their community. bear a significant resemblance to later monasteries.
academic.brooklyn.cuny.edu/history/dfg/jesu/topic2.htm
The Septuagint Greek (LXX)Translation
The second recension was the Septuagint Greek (LXX) which was translated from the Vorlage Text about 250 BC by 72 Jewish scholars in Alexandria (also known as the Alexandrian Septuagint, by way of distinction from other later translations also bearing the title of Septuagint, or LXX). This version became necessary because of the number of Greek-speaking Jews that were resident in Egypt under the favourable Ptolemaic Dynasty. It has been noted by most authorities that the LXX translation of the Vorlage Hexateuch (Genesis to Joshua) was particularly carefully done because of its revered position in the canon. The Eastern Christian Church still considers the LXX to be the authoritative OT text today.
ldolphin.org/barrychron.html