hi All,
I just installed Centos 6.4 on my new server box. I want to migrate or copy all the user accounts and password from my old server (Suse) to the new one. Please provide me with step by step if possible.
Many thanks

Sorry, this is not the place to come for 'step-by-step' directions. We'll be glad to help you, but you're going to be stuck on the passwords, I'm afraid.

First, and most obviously, copy ALL of the users home directories over to your new server. Be sure to retain the permissions and ownership of the copy, so read the man page on whatever utility you'll use (cp, scp, etc.). You can do this over the network (SCP), or to a local media (cp).
Second, look at your old /etc/passwd file, and compare it against your new one. You can do that with diff or grep...the "diff --suppress-common-lines" will give you JUST the lines (users) that are different from your old to your new files. Append those to the bottom of your new /etc/passwd file, after cleaning up the output a bit.
Third, give them new passwords...you can't (and shouldn't TRY), to copy them over. Give them all the same password, and tell them to change it when the log in.