I did it, and it wasn't too hard.

Here are some tips:

- when removing the midframe, begin from the side with the volume buttons like mentioned here

- the USB board can be bent a bit, it will probably still work fine if it did not crack when you removed it.

- The GT-i9515 also uses the GT-i9505 screen

- make sure that all ribbon cables are really fully attached, apply a bit of pressure

- when reattaching the midframe, make sure to clip in the power button side first, you will have a VERY hard time clipping it on there last. I had to remove the midframe again and start at that side