AppFrontier® has a number of partners who are experts in data migration and payment systems who we can refer you to for assistance if needed. Please contact support for any referrals.
For additional information and some technical assistance please check out our our Migration Documentation
For additional Migration help, here is an Open Source Data Migration tool provided by an outside source that can be helpful if you know JSON. Keep in mind Chargent doesn't support this migration tool since it's not a part of Chargent's products.