How to remove MongoDB duplicates?

Question

Yii

There is a user base, they have a unique _id field, and custom. id.
I need to remove all duplicates with id field and leave only unique ones.
On yii2, maybe there are some methods already ready?

I saw such an example, make a selection, create a temp_table with unique users by id.
drop the old one and copy the temporary one.
Are there any other options ?