Pushing Win 2k SP2 from a NT4.0 Server

I have a WAN that consists of 30+ Win 2k Pro Workstations, 1 Win 2k member server and 2 NT 4.0 servers functioning as the PDC and BDC. What I am trying to figure out is if my servers can push the Win 2k SP2 update to my users who need it when they log on. I would prefer to do this with out having to purchase MS’s SMS app. I am trying to avoid having to goto each individual workstation and do the install.