Upgrade HA to 64bit while preserving datadisk?

Hi all,

I have not been able to find a solution to my issue here in the forum or through Google, so here goes. Any help is greatly appreciated.

So, I have a Home Assistant OS (HAOS?) 32bit setup on my RPi 4. My datadisk is moved to an external SSD, but the SD is used for the bootup. Latest versions (non-beta) of everything.

For the sake of getting the VSCode and UCK add-ins, I would like to upgrade to 64bit. However, my datadisk has several hundreds of GB of data. Basically, I use it as a backup of my cloud data via SMB and another RPi running rsync.

Is there a way to do the upgrade while preserving the datadisk? If possible I would like to avoid including the whole datadisk in a snapshot (backup), and also not need to download everything again either.

Thanks in advance
Henrik