Our organization would like to convert all Person Accounts to Contacts. We would like the converted contact to be connect to an account named, "Generic Contact."  I looked into this a little and this is what I found out. 

Option 1:

Each Person Account has a record in both the Account table and Contact table.  The Contact table holds all the Person Acount information.  The Contact table has a field called IsPersonAccount which is marked true. I would like to change the IsPersonAccount to false, change the AccountId to that of the "Generic Contact" account and Delete the Account with the old AccountId.

Whenever I try to change the IsPersonAccount to false, I get an error "INVALID_FIELD_FOR_INSERT_UPDATE".

Option 2:

Now I can export the contacts to a csv file and  filter out all contacts with business accounts leaving the Person Accounts.  Then I can delete all Person Accounts and import the people in my csv file as contacts.  Finally, reconnect all compaigns using the PHP API.  

I would much rather change the AccountId and IsPersonAccount fields  (much less work).  Is there anyway to do option 1 or is there a better way of converting PersonAccounts to Contacts?