Customer Migration… more like customer confusion

I have recently been put on a customer migration project, making customers change web/app/retail experience. The company I work for has acquired another company in the same industry.

Everywhere I have seen this done before, the explanation to the customer is company 'x' has merged with company 'y'... creating company 'z'.

My company has re-skinned/rebranded the acquired company with the same brand and colour palette. The UX/UI are slightly different. We currently have two company x's on the App Store.

My company is now explaining to the customer. Hey, company 'x' has acquired company 'y' and made it company 'x.1', and now we need you to move from company 'x.1' to company 'x'.

I'm confused writing this, so the customer must be lost! The user fear will be around migrating money in wallets, accounts, passwords, transaction history, through physical and digital channels etc.

Does anyone know of this being done before? Or any UX customer migration advice/case studies or words of wisdom.

Thanks in advance for your help \o/