One must stop eating and drinking at 8:08 PM.
When Shabbos is over, at 8:50, one should say Baruch hamavdil Bein kodesh l’chol.
One should then switch into Tisha B’av footwear.
The only part of Havdallah that is recited on Saturday night is the blessing on fire. This can be said at home. It will also be recited in shul before Eichah.
After the fast, on Sunday evening, one should say the blessing on grape juice/ wine and the final blessing of Havdallah (like on Yom Tov)
if one needs to break the fast they should first make Havdallah as it is described above. However, instead of grape juice or wine, it should be said with orange juice or coffee.