Left over bits from home button replacement

I couldn't tell you exactly where the screws go...

The black piece with the copper hole is a ground for your battery, it goes under the battery connector with the hole on the bottom and the skinnier straight part pointing up, the screw that holds the battery connector on also holds this piece.

The larger rubber piece goes under the logic board on top of the display ribbon cables where they bend around the logic board.

The smaller rubber piece goes under the bottom speaker assembly about the ribbon cable for the lower microphone.

Leaving the rubber out will probably not hurt anything but if I were you I would put the battery ground piece back on, its very easy.