Updating auto-expiration for timeseries collection

Hi all,
I am using timeseries collection to store sensor data defined/create as below

 database.CreateCollection("SensorData",
     new CreateCollectionOptions { TimeSeriesOptions = new TimeSeriesOptions("Timestamp", metaField: "SensorId", granularity: TimeSeriesGranularity.Seconds), ExpireAfter = TimeSpan.FromDays(365) });
`
As per the above syntax am expecting  the document in the collection to be deleted after one year they were created.
Now  due to certain requirements I want to  change ExpireAfter to 2 years. how can I achieve this functionality in C#.
Any help will be appreciated .