You can remove the drives in this manner.  Mark them so they go back to the same slots prior to removal.  Then create your new RAID 1  on the new drives  and install your OS.  If you need to reinsert the old drives, power down, remove the current drives, then power up with no drives in the server.  Enter the Ctrl R bios and clear the configuration.   Power down, insert the original drives, then power up.   You will then accept the configuration from the drives, and your server should boot back up normally.  Regards,
Hi I dont have much experience with this so have a silly question. I have the above mentioned server and would like to know if I remove both the drives that is configured in a RAID 1, will this break the RAID?  I need to rebuild this server so what I would like to do is remove both drives, add two different drives, setup a new RAID 1 and install the server but still have the previous drives available as a backup. So if something does not work properly we can roll back. Will this work though, if I connect the two initial drives will it pick up as if it was never removed? Will the data on it still be accessible? Any assistance with this will be greatly appreciated. Regards  Hilton
DELL Power Edge R410 with Perc H700