Partition scheme change with clustered Index

Hi,

I have table which has 600 million records and also has the Partition on PS_TRPdate(TRPDate) column, I want to change it to another Partition PS_LPDate(LPDate).

So I have tried with small amount of data with following steps.
1) Drop the Primary key Constraints.
2) Adding the New Primary Key Clustered Index with new Partition PS_LPDate(LPDate).

Is it Feasible with 600 million records? Can anyone guide me for it? 
and How does it works with Non Partitioned Tables?

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