Install Sublime Text 3 on Linux via POSIX shell script - http://simonewebdesign.it/install-sublime-text-3-on-linux/

install_sublime_text.sh

#!/bin/sh

# Sublime Text 3 Install (last update: Monday 13 March 2017)
#
# No need to download this script, just run it on your terminal:
#
#     curl -L git.io/sublimetext | sh


# Detect the architecture
if [[ "$(uname -m)" = "x86_64" ]]; then
  ARCHITECTURE="x64"
else
  ARCHITECTURE="x32"
fi


# Fetch the latest build version number (thanks daveol)
BUILD=$(echo $(curl http://www.sublimetext.com/3) | sed -rn "s#.*The latest build is ([0-9]+)..*#\1#p")

URL="https://download.sublimetext.com/sublime_text_3_build_{$BUILD}_{$ARCHITECTURE}.tar.bz2"
INSTALLATION_DIR="/opt/sublime_text"


# Download the tarball, unpack and install
curl -o $HOME/st3.tar.bz2 $URL
if tar -xf $HOME/st3.tar.bz2 --directory=$HOME; then
  sudo mv $HOME/sublime_text_3 $INSTALLATION_DIR
  sudo ln -s $INSTALLATION_DIR/sublime_text /usr/local/bin/subl
fi
rm $HOME/st3.tar.bz2


# Add to applications list and set icon
sed 's/Icon=sublime-text/Icon=\/opt\/sublime_text\/Icon\/128x128\/sublime-text.png/g' > $HOME/.local/share/applications/sublime_text.desktop

echo '
Sublime Text 3 installed successfully!
Run with: subl
'

Nice, finally, thanks for pointing that out.

For the migration, unless you have fancy stuff, all you need to do is save your user configuration somewhere (e.g. one convention is to have a dotfiles repository, but you might as well just make a gist or keep it somewhere else), also keep note of your plugins and themes. When you're ready just do rm -rf $(which subl).