@jeder yes, that’s exactly what you need to do — delete partition and create a new one instead of it (without rewriting any old partition signatures), fdisk doesn’t apply the changes immediately so you can do a dry run first
more seriously though, if you don't mess with the start of the partition and just expand it, it should work fine you can use something like cfdisk or maybe even gparted (at least it's a bit easier for me that way, ymmv)
