If you want to reverse the assignements, switch eth0 and eth1 at the end of the entries. Or delete one of the entries.
Next you will need to edit this file:
/etc/sysconfig/network-scripts/ifcfg-eth0
=Example=
<small>
HWADDR=00:1d:60:b5:43:66
</small>
You will need to adjust the HWADDR to match the MAC address of the card you wish to make eth0. Note: if you wish to keep eth1 active, you will also have to edit ifcfg-ith1 as well.
These changes will only take effect after a reboot.
'''Please exercise care. Improperly modifying this these file may render your system without network or even not boot properly.'''