This assumes that git is already installed on your computer
Step 1: Download vue-tools from github to your computer
git clone https://github.com/vuejs/vue-devtools
Step 2: Enter the downloaded vue-tools directory and install
cd vue-devtools
npm install
npm run build
Step 3: Open chrome more tools-->Extensions-->Check developer mode-->Load unzipped extension
Step 4: Restart chrome-->Open console