Database Duplication Via RMAN

I have 2 identical databases set up as follows:

- Version: Oracle 11gR2 (64 bit)
- OS: Windows Server 2008
- File System: ASM (with GRID Infrastructure)

Both instances are virtually identical... Same directory structures, same SYS passwords. The only thing that differs is the instance name (one is ABC, the other is XYZ).

Now, both databases are up and running, both have users on them, and both can accept remote connections. What I want to do is set up a very simple 'copy' system so that everything can be extracted (via RMAN) from the first database, and replace the database on the second. (Then, the user can log into XYZ with the same usernames/passwords they used on ABC.)

Here's what I'm doing so far:

On the 'source' database (ABC) I run RMAN as follows:
rman target / nocatalog
configure controlfile autobackup format for device type disk to 'C:\temp\CF_%F';
configure channel device type disk format 'C:\temp\bkp_%U';
run {backup database; backup archivelog all; }

Now, I'm not completely sure of what to do on the 'destination' database. I've seen multiple web pages with instructions that require the creation of a new instance using 'oradim' and the creation of a new password with 'orapwd'. However, is that necessary if I have the same sys password on both databases, and I want to use the same XYZ instance name on the destination machine?

Would it work if I used 'delete database' on the destination, and then used the RMAN 'Duplicate database to XYZ backup location 'C:\temp\'? Or does it HAVE to be a new instance created with oradim?

And if I DO have to use oradim to create a new instance, will the data be accessible through XYZ too?