Using Time Machine on the new MacBook after migration
Hello,
I have an external hard disk that I use for time machine. I changed my laptop from Macbook Pro 15" to Macbook Pro 13" and I used this external hard disk to migrate from my older Macbook to the new one. Now I want to use my external hard disk to back up my new computer but the problem is that I think when I try to backup it makes the backup on top of everything from my older computer. The back up on the new Macbook takes 250GBs on top of 600-700GBs. I don't think that my backup should take 900GB of space. I think 600-700GBs is from the older computer and I don't want to have an unnecessary backup on top of what I actually need...
So what should I do to get rid of that 600-700GB properly , and then set the external hard disk as the new time machine for my new Macbook ?
My OS is 10.8.4.
Thank you
Macbook Pro