Should I remove the address from the old website?

I have a new client. They want to optimize and bring-in traffic to a brand new website rather than having me work on their present website. They want to keep the preserve present website as a company portal. I`m planning to use the secondary office address for Google local listing purpose. The primary office adress listed in the Google knowledge panel. But the problem is that the secondary address is already listed on the present website. So, should i remove the address from the present website.