Un-assign Plant from Company Code

I just want check and make sure that anyone got into any issues of re-assigning an existing plants from one company code to a different one?

1. Plants 01, 02, 03,.....25 etc are currently belongs to company code A1, but couple of plants will be moved to a new company code B1 soon in ECC. We will un-assign the plants from company code A1 which are moving to company code B1.

2. What are the consequences and how to handle them in SRM? Do we need to delete the plants in SRM which are moving to new company code B1 from company code A1. If yes what is the best way to delete them from company code A1?

Thanks for your input in advance.

VNR