How to update a foreign key field to null before saving an instance

I have a model x which has a field named y. y is foreignkey. Assuming y’s value is set to z(which is an instance), i want to remove that z value and set it to empty. How can i do that?

now x.y==z(instance)

i want to set it x.y=None or null which is an update operation.
is there some sort of operation like x.y.update(None) ?

or removing that field value is also fine

@KenWhitesell any suggestions?

Assuming that nulls are allowed for that FK reference, x.y=None followed by should do it.
If you had a number of them to update, you could use either the update or the bulk_update method on the model class

i was so dumb, i spent more than an hour trying x.y=None without saving.
Thanks a lot ken!!