It's been a while since I updated the software on the Raspberry Pi Zero W that I had installed in my telescope hand controllers, mainly because I was afraid that it would turn out to be a huge time sink to get it as stable as it was originally.  This turned out to not be the case.  The upgrade process going from Jesse to Stretch is quite slow, but very straightforward and I was able to multitask while doing it.

As root, upgrade the operating system to the latest version:

sed -i 's/jessie/stretch/g' /etc/apt/sources.list
apt-get update
apt-get upgrade -y
apt-get update
apt-get dist-upgrade -y

As root, remove all of the old libindi packages for Jesse:

apt-get remove atikccd fliusb-dkms fliusb-source indi-aagcloudwatcher \
  indi-aagcloudwatcher-dbg indi-apogee indi-apogee-dbg indi-asi indi-asi-dbg indi-bin \
  indi-dbg indi-dsi indi-dsi-dbg indi-duino indi-duino-dbg indi-eqmod indi-eqmod-dbg \
  indi-ffmv indi-ffmv-dbg indi-fishcamp indi-fishcamp-dbg indi-fli indi-fli-dbg \
  indi-gphoto indi-gphoto-dbg indi-gpsd indi-maxdomeii indi-maxdomeii-dbg indi-qhy \
  indi-qhy-dbg indi-qsi indi-qsi-dbg indi-sbig indi-sbig-dbg indi-sx indi-sx-dbg \
  libapogee3 libapogee3-dev libapogee-dbg libfishcamp libfishcamp-dev libfli1 \
  libfli-dev libindi1:armhf libindi-data libindi-dev libqhy libqsi7 libqsi-dbg \
  libqsi-dev shoestring usbfocus

As root, install all of the new ones for Stretch (directions from here):

apt-get install cdbs libcfitsio-dev libnova-dev libusb-1.0-0-dev libjpeg-dev \
  libusb-dev libtiff5-dev libftdi1-dev fxload libkrb5-dev libcurl4-gnutls-dev \
  libraw-dev libgphoto2-dev libgsl-dev dkms libboost-regex-dev libgps-dev \
  libdc1394-22-dev

curl -o libindi_rpi.tgz -L http://indilib.org/download/raspberry-pi/send/6-raspberry-pi/9-indi-library-for-raspberry-pi.html

tar -xzf libindi_rpi.tgz

dpkg -i *.deb 2>&1 | tee install.log

I also had to reconfigure (pair/trust/connect) my Bluetooth controller using my notes from when I initially setting it up.