rxTools 3.0 Web-boot for entering Pasta Mode.
BigBlueMenu for installing System CIA to SysNAND Pasta Mode.
FBI for deleting NAND titles which don't match.
Personally I recommend the same version number.
i used qrcode from rxtools 3.0 beta 2 no luck
You must keep 9.0 KOR SysNAND safely because it also contains KOR Secureinfo_A and ticket.db.
you can use spider rop chain with browser, it support rxtool, reinand, and gateway; http://dukesrg.github.io
he suggest, region change sysnand to jap, usa, or eur, then upgrade to 9.2, downgrade 2.1 and dump OTP.
if you just need emunand feature, it not need this work
but, if you want to use a9lh, you require legit SecureInfo_A for region change, if not, device will brick.
always backup your device sysnand before do this action.
btw, i think, actually you don't need downgrade to 4.x, maybe can region change direct in the 9.0. @MelonGx 's method show this.
how exactly to use spider for example if i want to use gateway i enter http://dukesrg.github.io/?launcher.dat is this right? i tried this but no luck
you mean from 9.0 to 9.2? if i want to downgrade to 2.1 to get otp did i must create emunand just like plailects guide and use otp helper?