Did you create a new Vendor Record, or just change the name?  If you just changed the name it should work fine.  

If not, use the Pay-to Vendor field under the Payment Tab of the Vendor.  This assumes you have Vendor Relations turned on.  Do you have this field available?  

We created a new vendor.  With adding the Remit -To information, will it link with the other vendor invoices?  Do we need to set up the Parent Account to tie the two vendors?

I would recommend making the new one the parent and even deactivating the old one once things are cleaned up.