if you don't know how to work with vi, perhaps you should have a look on some pages in the internet first. Google is your friend. Perhaps you can start with http://www.cs.colostate.edu/helpdocs/vi.html. vi is a very powerful editor, but when starting with it, it looks very complicated.
I can give you a really short explanation, what to do:
- log in via ssh, change to root with su - ( note the blank between su and - )
- then first of all, make a copy of the original file with cp /etc/inittab /etc/inittab.original and then start modifying the file with
- type vi /etc/inittab to start vi with the file
- goto the end of the last line
- press i to enter insert mode of vi
- goto a new line by pressing enter key
- type "::sysinit:/usr/sbin/sshd"
- press ESC to enter command mode of vi (leaving insert mode)
- type :x and press enter key to quit vi with saving the file
- or if you don't want to save the file then type :q! and enter key
Be careful when you're using vi the first time. Perhaps you should try to edit some own files first. Perhaps you try to create a own file with vi myownfile.txt and enter some chars to it. then call it again and modify it.
Another possibility is to install nano. But for nano I can't help, perhaps others can.
Hope that helps.