I changed the partition table on one HDD from GPT to MBR/MSDOS but I realized (too late) that it affected all partitions on the same HDD. Basically I lost data on the secondary partition which I wanted to keep.
I used gparted to perform the change of partition type.
How can I recover the data I had on my secondary partition? Nothing has been formatted, I've "only" changed the partition table (i.e. I guess destroy the previous partition table).
Recovering the data that was loosed is of more importance than getting to a HDD with MBR at the moment.