Installation DS 4.0 on server where DS 3.2 exists

Hi,

I would like to install new DS 4.0 on the server where the old DS (ver: 12.2.2.3.) exists without uninstall it.

Do you have any experience with this?

Or better way is to unistall old DS (there is BO 3.1 also) and install DS 4.0?

Can BO 3.1 and DS 4.0 coexists?

Regards