upgrading disc capacity

[Peter J Slot]

Hi,

We have a Dell poweredge 2500 with buildin aacraid with 3x18.4 GB using 
raid5.
The machine is running RH9

Recently one of the disks died. Can I replace the 3x18 GB disks with 
Seagate 36GB discs.
This by replacing first the dead disc, rebuild array. Change second disc 
and so on... until I have 3x36 only using 50% of the discs.
After this I would like to expand the container to use the full 
capacity, is that feasable?
If yes, what would the procedure be?

Regards,
Peter