diff --git a/app-server/puma/README.md b/app-server/puma/README.md
index 782eff8..6225ed0 100644
--- a/app-server/puma/README.md
+++ b/app-server/puma/README.md
@@ -1 +1,39 @@
 Alternative configuration file for the `puma` application server. Copy it under `/home/git/gitlab/config/`.
+
+## How to replace unicorn with puma
+
+The easiest solution is to create a separate branch from the latest stable release
+and work from there. Then, with every release we can merge the stable branch into ours.
+Replace `latest-stable` with the latest stable branch.
+
+```
+su
+service gitlab stop
+su - git
+cd gitlab/
+git checkout latest-stable
+git checkout -b puma
+sed -i 's/unicorn/puma/' Gemfile
+
+# For mysql
+bundle install --without development test postgres --path vendor/bundle --no-deployment
+
+# For postgres
+bundle install --without development test mysql --path vendor/bundle --no-deployment
+```
+
+### Update GitLab version
+
+When a new release is out all you have to do is merge it in puma branch.
+
+```
+# As git user
+
+cd /home/git/gitlab/
+git checkout master
+git fetch
+git checkout puma
+git merge latest-stable
+```
+
+Then follow the official update instructions about migrations and the bundle install command.