[CentOS] Raspberry PI 3

Hi all

I downloaded the RPI3 image:
CentOS-Userland-7-armv7hl-Minimal-1603-RaspberryPi3.img.xz

how do I resize the root FS?  My Sd card is 32G and I am only using 2G of
that.

also I thought the RPI3 as was 64 bit. When I downloaded the
aarch64.img and tried that it did not boot.
I thought the RPI3 supported this image. perhaps not.

Thannks,

Jerry