DELL T610 with perc H200 increase Raid 1 size how to?

Hey,

we got a T610 with perc H200 and 1x150GB and 1x300GB (<-this was build in cause the old one had an error, both SAS 15k) in Raid 1

My plan is to change the old 150gb to an another 300gb and let build up the array after this.

but how to use the free space after this? Could i delete the virtual disk and build up new with all data? without loosing my data and without reinstalling?