RDoc-3381 Cannot change UID:GID of container user

Documentation/6.0/Raven.Documentation.Pages/migration/server/docker.markdown

@@ -53,11 +53,30 @@ E.g. `chown -R 999:999 $TARGET_DATA_DIR`
 
 ## Customizing the RavenDB data directory owner user UID/GID 
 
-In order to use a custom UID/GID for the `ravendb` user please build the Ubuntu container image yourself providing desired **UID** and 
-**GID** values, using the following arguments upon build:  
-**UID**: `--build-arg "RAVEN_USER_ID=999"`  
-**GID**: `--build-arg "RAVEN_GROUP_ID=999"`  
-E.g., `docker build --build-arg "RAVEN_USER_ID=999" --build-arg "RAVEN_GROUP_ID=999" <...>`  
+To customize the **UID** and **GID** of the `ravendb` user (e.g. to match your host user or for volume permissions), you can build your own image using the official `ravendb` base image. 
+
+{CODE-BLOCK:csharp}
+FROM ravendb/ravendb:7.0-ubuntu-latest
+
+ARG USER_ID=1000
+ARG GROUP_ID=1000
+
+USER root
+
+RUN groupmod -g "${GROUP_ID}" "ravendb" && \
+usermod  -u "${USER_ID}" -g "${GROUP_ID}" ravendb && \
+chown root:${USER_ID} /etc/ravendb/settings.json && \
+find / -xdev -uid 0 -gid 999 -exec chown "root:${GROUP_ID}" {} +
+
+
+USER ravendb
+{CODE-BLOCK/}
+
+### Build Instructions 
+
+1. Save the above as `dockerfile` 
+2. Open a terminal in that directory 
+3. Build the custom image with your desired UID and GID: `docker build --build-arg USER_ID=YourUserID --build-arg GROUP_ID=YourGroupID -t image-name -f dockerfile`
 
 ## Migrate files and data