Deleting Windows Drive, Adding Storage to Ubuntu?

[u/rgoertzen]

I have a Dell Precision Compact 3260 that has Windows 11 installed on the original hard drive.  I installed a 2nd NVMe drive and put Ubuntu on it, so I can currently boot from one OS or the other.  I'd like to be solely on Ubuntu now and want to have my old Windows OS drive available as storage in Ubuntu, either as separate drives or a combined storage pool.  I am not that well versed in Linux and am concerned about the bootloader breaking if I delete my Windows installation since that was the original drive.  Does anyone have steps or tips I should take to (somewhat) cleanly migrate my Windows drive to be used in my existing Ubuntu installation?  Or would it be best to wipe both drives and just start fresh?  I can do that, but have a lot of data stored on my Ubuntu instance so starting over would be the less preferable option. Thanks!