Expanding logical drive using Raid 1

Hi,

Server 2008 r2
ProliantDL380 G6

We have 2 physical disks with 2 logical drives on them - each using separate RAID 1.

Logical Drive 1 - C: = OS 

Logical Drive 2 - I: = Data

I would like to remove the I: drive from windows disk management as it is not used, then delete it using the HP Array Confguration Utility, leaving only Logical Drive 1 (C:). 

Then I'd like to expand that Logical Drive, to create 1 large disk - RAID 1 across it.

This sounds a simple task to me, but can I do this without affecting anything?  I can not afford to wipe Logical Drive 1 - C: of any data.

Thanks in advance.