How do the waiting instruction and replacement of Judas unfold?

Addressing Theophilus, the narrator recalls the former treatise concerning what Jesus began to do and teach, up to his being taken up after giving commandments through the Holy Ghost to the chosen apostles. Jesus shows Himself alive after the passion with many proofs, appearing forty days and speaking of God’s kingdom. Eating with them, he commands them to remain in Jerusalem for the Father’s promise they heard from him: John baptized with water, but they will be baptized with the Holy Ghost not many days hence. Asked whether He now restores Israel’s kingdom, He says times and moments in the Father’s power are not theirs to know. They will receive the Holy Ghost’s power and witness in Jerusalem, Judea, Samaria and the earth’s uttermost part.

As they watch he is raised, and a cloud receives him out of their sight. Two men in white stand beside them as they look up, asking why the men of Galilee look heavenward and saying Jesus will come as they saw Him go. They return from Olivet, near Jerusalem within a sabbath day’s journey, and go to an upper room. Its residents are Peter, John, James, Andrew, Philip, Thomas, Bartholomew, Matthew, James of Alpheus, Simon Zelotes and Jude brother of James. They persevere with one mind in prayer with the women, Mary Jesus’s mother and His brethren.

In those days Peter rises among brethren, about 120 together. He says scripture spoken through David by the Holy Ghost about Judas must be fulfilled. Judas led Jesus’s captors and shared this ministry. He possessed a field of iniquity’s reward; being hanged, he burst in the midst and his bowels came out. This became known throughout Jerusalem; the field was called Haceldama, field of blood. Peter cites Psalms about desolate habitation without inhabitants and another taking his bishopric. One of those accompanying them throughout Jesus’s coming and going, from John’s baptism to His being taken up, must become a resurrection witness with them. They appoint Joseph called Barsabas surnamed Justus and Matthias. They pray to the Lord knowing all hearts to show which of the two He chose for this ministry and apostleship, from which Judas fell by transgression to go to his own place. They give lots; the lot falls to Matthias, numbered with the eleven.