How to set SEO field data programatically (PHP)

[jakepm]

We are switching from a site that uses custom fields on entries to set SEO data.

The legacy fields are still in place, along with the new SEO field, for all relevant channels.

To copy over the existing SEO field values, we are planning to write a script that sets the SEO plugin field values for each entry by just reading from the legacy fields. Then we can delete those fields and update the template layouts to use the SEO hook.

My question is, what format should the data be in when setting a value for the SEO plugin field? I assume an array but am not sure what key values and structure to use.

PS. We only have the meta title and description in the legacy fields.