To install it on a Debian based system simply do
# Install latest JDK
sudo apt install openjdk-8-jre-headless
# install unzip if not installed yet
sudo apt install unzip
# get latest sdk tools - link will change. go to https://developer.android.com/studio/#downloads to get the latest one
cd ~
wget https://dl.google.com/android/repository/sdk-tools-linux-4333796.zip
# unpack archive
unzip sdk-tools-linux-4333796.zip
rm sdk-tools-linux-4333796.zip
mkdir android-sdk
mv tools android-sdk/tools
Then add the Android SDK to your PATH, open ~/.bashrc in editor and add the following lines into the file
# Export the Android SDK path
export ANDROID_HOME=$HOME/android-sdk
export PATH=$PATH:$ANDROID_HOME/tools/bin
export PATH=$PATH:$ANDROID_HOME/platform-tools
# Fixes sdkmanager error with java versions higher than java 8
export JAVA_OPTS='-XX:+IgnoreUnrecognizedVMOptions --add-modules java.se.ee'
Run
source ~/.bashrc
Show all available sdk packages
sdkmanager --list
Identify latest android platform (here it's 28) and run
sdkmanager "platform-tools" "platforms;android-28"
Now you have adb, fastboot and the latest sdk tools installed