Xero Outh 1.0 to 2.0

Hi

We have a PHP \ Laravel application that connects to our database, and syncs invoices to Xero. It uses Outh 1.0 which is being depreciated in December. We need someone to move the code over. For secutity reasons, I cannot provide the code in this post, but it is of course the connection string, and all of the parts of the code that enter data into Xero. The applicaton is not big at all, there are 5 screens in total. If the work is more than expected once seen, a bonus will be paid so it is always fair.

Thanks

Dave