Change field type from Choice to List(with reference specification)

[fV]

Hello! New to servicenow, I'm trying to change an existing field type from choice to list in order to allow for multiple choice selection. I read that just changing the data type of a field which already has data (like the one I'm trying to change) should be avoided. How can I transfer the data from the old field to the new one? 

[Hitoshi Ozawa]

1. Create a new field of type List.
2. Copy data from Choice column to List column using script
3. Delete the Choice column

[Hitoshi Ozawa]

Note that Choice is a String from sys_choice table while List is a reference to an another table.

[fV]

Would I be able to populate the List field with previous selections from the Choice field? I was able to change the field type, but now filtering by this new field type does not show old data even though it seems to still be there. 

[bammar]

Ah yes , i was answering it originally imagining it was a reference field to List Collector transfer