As was for i9300. But as it states. After memory replacement. Which is a very hard thing to do
You have do desolder the old memory chip from pcb and put another one in its place.
After that you'll also might be needing Samsung's proprietary box-jig to provide power to phone (might not. For some it was doable with any UART providing box and if I remember 301k cable)
So if it dies either good luck fixing it or send it to Sammy to fix it.