How do you manually specify a network interface when working with DHCP?

I cant use YaST because when it rewrites the file without checking the syntax and tries to restart it with the incorrect syntax. I cant do anything about that since it will write over the dhcp file i already i have.

The current configuration in YaST contains my one of my NIC's, eth0. Now i want to use my other NIC instead which is eth1. YaST cannot start and save the configuration properly, thats why i need to manually specify Network interfaces manually for dhcpd.

I need to know how to specify it so my dhcpd.conf file can use the proper NIC.

try ifdown.

And Yast should be able to be configured for static IP addressing to eth devices.
'locate ifcfg-eth0'

in that directory, add a ifcfg-eth1 text file script with BOOTPROTO=static