If the network has chanserv and the 2nd op has sufficient access, he could issue /msg nickserv invite #channel <nick>
The <nick> parameter might not be required.. I've seen networks set up both ways.
If this isn't an option, or doesn't work, then the 2nd op has to be invited, or have the channel founder identify to chanserv with the channel password, then join the channel and have the founder remove the +i
Additional Info: The Rogue operator was given "owner rights" from the previous "owner/founder" As a show of his new power, he decided to make the channel by "invite only" Now no one can enter the channel including me as a OP. This channel has been around a long time in our league organization.