If you're familiar with rerolling with SIF, perhaps you know the Root Browser method?
Rerolling for BGHS is quite similar to that. You can find the tutorial on the Wiki page of this Reddit here or you can follow what I'm about to say.
First of all, there's quite a few number of ways to do this. The most easiest being Bluestacks, of course. If you plan to do it without Bluestacks, I'm pretty sure you have to uninstall and reinstall the game continuously and keep going through the tutorial.
For Bluestacks, there's a tutorial on the LLSIF Root Browser method which was an older method of rerolling before someone created SIFAM. Here are the steps below:
- Download BGHS and Root Browser.
- Open up Root Browser
- Go to Data > Data > jp.colopl.bgirl > Shared_Pref
- Open BGHS
- Continue playing tutorial until you can roll once during the tutorial and an additional two times because you start off with 30 gems
- Once completed, close BGHS and go back to Root Browser
- Refresh if needed until you see a file which ends with .XML
- Left click and hold onto the XML file name, rename the file, you keep your data in it or delete if unwanted
- Repeat from step 4 and below