GAM - Move assignements to new topic, merge topic?

[Bev]

We have been creating a new topic for each date, and some classes have now hit 100 topics which appears to be the maximum.

I want to move all the course-work items from March to July into a single topic called '2019-2020' but I can't work out how to update the topic id through GAM?

I can list them, and I can see all the topic ids but I cant find the right command to change it.

 

>gam update course-work course 62828931577 workid 54705092119 CourseTopicID 54705092120

>gam update course-work course 62828931577 workid 54705092119 TopicID 54705092120

 

both fail.

 

I can list the specific piece of course work like this

gam print course-work course 62828931577 workid 54705092119

 

but I cant work out how to update any of the fields.