SEP two managment console deploy

Hi,

one of customer having SEP SBE on presmises license 40nos but the proeblem is 20 license is expired and 20 licenses are remainig,  and the other thing is SEP SBE on premises version has been discountinue, as of now customer needs only 20 licenses, so just wanted to know if we give SEP SBE & SEP enterprise version can work in same network, is there any option we can upgrade from SEP SBE To SEP.

* two management console can work in same env

please help me with above as it is urgent..

thanks in advance.!