Copy data from the same student In the same class

Hello!

I got a problem, I started my courses adding students from  a .cvs, though, I had to link my courses to Google classroom (1 month after the course starting) but I got some students duplicated and now I want to copy at least all the attendance from some of those students to the new profiles in the same gradebook.

Is there something to do this quicker and easier?   

Hello Danomora (I saw the pictures, just erased them for security reasons),
 The Google Classroom link does not depend on the student's name. If you change the e-mail field on the original student by that
of Google, erase the new students and link again with Google Classroom it will work.
 In order to link students, e-mail is checked first and if missing, iDoceo tries to match a name