100:15 The kohanim are not allowed to start the bracha that G-d has sanctified them with the holiness of Aaron, etc. until the shliach tzibbur has completely finished the word “kohanim.” Similarly, the shliach tzibbur is not permitted to prompt the kohanim with “Yevarechecha” until after the congregation has finished saying Amen to the bracha recited by the kohanim. This is also true with the Amen that the congregation responds with after “v’yishmarecha,” “vichuneka,” and “shalom:” the shliach tzibbur must wait until after the congregation has finished saying Amen before continuing. With “Ya’eir,” “Yisa,” and “Sim Shalom.”
The kohanim do not turn away from facing the congregation to face the aron (ark) until the shliach tzibbur begins the bracha of Sim Shalom. They don’t return their fingers from their outstretched position until they have turned away from the congregation, and they don’t descend from the platform until the congregation has finished saying Amen after “…es amo Yisroel bashalom.”
100:16 When the kohanim turn around, both at the beginning of duchening and at the end, they should only turn to the right. Therefore, at the beginning, when they are facing east, they should turn south and then west. Later, when they turn back to the east, they should do so by way of the north. When they descend from the platform, they should face the aron (ark) slightly and back away, like a student leaving his teacher. When the kohanim put their shoes back on, they should not touch them; if they did touch their shoes, they need to wash their hands.