Impact of possible SRM Objects

Hello Experts,

We are planning to migrate several objects such as Purchase Req, POs Contract etc - from existing Plants to New plants in a Newly created Company Code in ECC.

We also have open Shopping Carts created in SRM 7.02.  Hence,  I seek your guidance as to what are the possible activities to take into consideration as far as SRM is concerned. We are in Classic Scenario hence, I'm only concerned about Shopping Carts and  I remember to change the Plant / cost objects attributes in Org Structure. (not changing Delivery Address)

Also, how do I change the Plants in open Shopping Carts?  Any input woule be highly appreciated.

Thanks

S