Changing CRM can be complex, this is why few companies feel confident to face that challenge. A mix of investment done and blind leap into something unknown generally stop organizations from it. When an organization decides to discontinue the CRM then it is better to have a clear picture of the project complexity to plan it for the best outcome.
No two CRM work the same way: Prepare the new one for what it can do better keeping in mind the business workflows then preserve the general approach when possible.
Data architecture and Data Set analysis:
Study the architecture, then adopt the data architecture that matches the new CRM.
Do not migrate in one shot:
Create a first migration as a test, let the organisation familiarise themselves with the new tool. Then once everything is properly understood and settled down, decide the Friday-deadline to move all data. Perform the migration during the weekend or a country holiday to let them start with the completely updated new CRM form the very Monday.
Extract from Managing Sales Pipelines with Pipedrive CRM