We do not have a way to directly send a campaign to another account. There are a couple of options available to you:
Our Custom Services Team can transfer the template for you. If you would like this there is a cost associated, and I can set up a call for you to speak with one of the team members to get more info.
The other option is to manually move the information over. You can select the same template in the other account, copy the Style Sheet into the other account, then block by block go to the HTML Code and copy it over. If you are going to go this route, make sure that you are logged in to each account in a different browser (i.e. One account in Firefox while the other is in Chrome), so that you do not get logged out after each step.