DHCP and Netware

We have a NetWare 4.11 server with DHCP turned on and the lease expires every 10 days (as opposed to the obligitory 3 days). For the second time in the last month and a half, our DHCP table is corrupt (cause unknown) and we are working with our corporate IT department to rebuild the table but they are saying that us in the local IT department have to go around to each workstation (100+), and manually release the IP address manually before re-building the table. Is there a way to automaticallyrelease the IP addresses without the hassle of going to each workstation to release the IP addresses – the last time we did this, it took about 2 hours to do? I think that there might be a way to do this, but am not sure – any help is appreciated.