Yup, sure you can. I've done it loads of times. Sometimes I try and pull/cut away any excess rockwool if possible before transplanting. Just make sure if there's any plastic around it, that you take that off first.
A dispensary in cali... 1 died today sadly... i took it out of the rockwool cube and cut around it i know for sure i hurt 2 roots but it might be overwatered as well... i have no hope for it. the other, is doing just the opposite and growing strong!