replacing a value in a field

Hi All,

I have a file yum.conf that has a field called gpgcheck
this field sometimes has a value of 0 gpgcheck=0 and at other times it has a 1.
I need to check the value and if it is a 1 change it to a 0
any ideas?

thanks,

Gartie

sed -i.bak 's/gpgcheck=1/gpgcheck=0/' yum.conf