How to transport a specific info object? I tried to change it and then save but the transport request won't appear. How to manually transport that object? 

1. Administrator Workbench (RSA1), then Transport Connection  

2. Object Types, then from the list of objects put the requested one on the right side of the screen (drag & drop)   3. Click "Transport Objects", put the development class name and specify the transport (or create the new one)   4. Transaction SE01, check transport and release it   5. Move the transport up to the another system.    

If you change and reactivate the infoobject, but get no transport request, this means that your infoobject is still in $tmp class.  

go in to the maintenance of the infoobject, menu extras, object directory entry and change the development class. at this point you should have a pop-up requesting a transport request   

If you're not getting a transport request when you change and activate, it could also be that the InfoObject is already on an open transport. 

When you collect the object in the transport connection as described above, you will see in the right hand pane an entry called Transport Request. If there is an entry here, the object is already on a transport and this gives you the transport number. 

You can then use SE01 or SE10 to delete the object from the existing transport if that is what you want to do then, when you change and activate the object again, you should be prompted for a transport request. Alternatively, you can use the existing transport depending on what else is on it.