diff --git a/README.md b/README.md
index ed5d3ad2..28f1a260 100644
--- a/README.md
+++ b/README.md
@@ -8,3 +8,19 @@ Please report [issues on YunoHost bugtracker](https://github.com/YunoHost/issues
 You can live test any changes by adding `/edit` to the URL on
 [yunohost.org](https://yunohost.org). For example, if you make changes to
 [apps.md](./apps.md), you can test them on [yunohost.org/#/apps/edit](https://yunohost.org/#/apps/edit).
+
+## Regenerate the css
+
+We use scss to manage the css. If you want to change it, you must rebuild it.
+
+First install npm, then in the root folder of this repo, install sass: `npm install sass`
+
+Finally you can rebuild the css with (You can replace `expanded` by `compressed` if you want):
+
+```bash
+./node_modules/sass/sass.js themes/yunohost-docs/scss:themes/yunohost-docs/css --style expanded
+```
+
+Source:
+https://sass-lang.com/guide
+