The below videos are guidelines only, and you should always refer to the full PDF for what you need to do for each grade. 

Taijiquan Instructor Grades PDF

Pre Instructor Test PDF
 (This is only required for those who have not gone through the student grades and passed grade 8)

Taiji Form
Single Push Hands
Chee Sau
Double Push Hands
Kick Defence
Large San Sau
Knife Defence