Modifying or deleting fields in the extended recipient schema

Hi,

I have a question about modifying or deleting fields in the extended recipient schema.

Modify field: Can I just modify directly from the code below and save?

<attribute desc="accountNumber" label="accountNumber" length="15" name="accountNumber"  type="string"/>

Delete a field: Can I remove the above line of code completely from the extended recipient schema and save?

Thanks,

ED