Change chart of accounts for existing company code

Hi Experts,

When I am going to change the existing chart of accounts of 2 company codes.(RML and RTL)

I wrongly assigned in OB62...when am going to change the COA and group COA not getting changed below mentioned error showing

Reset company code data before changing the chart of accounts

Reset the company code getting error attached screen shot.

Note: their is not documents in these 2 company codes.

I want to create group chart of accounts to these 2 company codes.

In OB13, how many COA need to create? and how ?

Please explain with more details.

Thanks in advance

Srinath