how to convert sass 4 to 5 code example

Example 1: Error: Node Sass version 5.0.0 is incompatible with ^4.0.0.

with npm =>
1.npm uninstall node-sass
2.npm install node-sass@4.14.1
with yarn => 
1.yarn remove node-sass
2.yarn remove node-sass@4.14.1

Example 2: node-sass run

npm install node-sass
node-sass ./styles.scss -o ./styles.css