how to upgrade old macbook to latest os

5:54

7:58

4:07

4:49

14:32

5:16

9:44

10:50

4:39

3:40

1:35

1:52

2:41

6:18

8:14

7:15

8:07

10:04

4:02

16:55

14:11

2:16

12:46

6:29

12:46

11:13

10:33

8:44

8:34

6:29

20:00

25:39

3:12

11:39

3:43

4:05

7:22

2:16

15:00

10:32