Update README.md

Added detailed instructions to migrate from ollama-webui to open-webui, preserving and not preserving existing data

README.md

@@ -219,9 +219,48 @@ docker rm -f open-webui
 docker pull ghcr.io/open-webui/open-webui:main
 [insert command you used to install]
 ```
-
 In the last line, you need to use the very same command you used to install (local install, remote server, etc.)
 
+### Moving from Ollama WebUI to Open WebUI
+
+Given recent name changes, the docker image has been renamed. Additional steps are required to update for those people that used Ollama WebUI previously and want to start using the new images.
+
+#### Updating to Open WebUI without keeping your data
+
+If you want to update to the new image but don't want to keep any previous data like conversations, prompts, documents, etc. you can perform the following steps:
+
+```bash
+docker rm -f ollama-webui
+docker pull ghcr.io/open-webui/open-webui:main
+[insert the equivalent command that you used to install with the new Docker image name]
+docker volume rm ollama-webui
+```
+
+For example, for local installation it would be `docker run -d -p 3000:8080 --add-host=host.docker.internal:host-gateway -v open-webui:/app/backend/data --name open-webui --restart always ghcr.io/open-webui/open-webui:main`. For other installation commands, check the relevant parts of this README document.
+
+#### Migrating your contents from Ollama WebUI to Open WebUI
+
+If you want to update to the new image migrating all your previous settings like conversations, prompts, documents, etc. you can perform the following steps:
+
+```bash
+docker rm -f ollama-webui
+docker pull ghcr.io/open-webui/open-webui:main
+# Creates a new volume and uses a temporary container to copy from one volume to another as per https://github.com/moby/moby/issues/31154#issuecomment-360531460
+docker volume create --name open-webui
+docker run --rm -v ollama-webui:/from -v open-webui:/to alpine ash -c "cd /from ; cp -av . /to"
+[insert the equivalent command that you used to install with the new Docker image name]
+```
+
+Once you verify that all the data has been migrated you can erase the old volumen using the following command:
+
+```bash
+docker volume rm ollama-webui
+```
+
+
+
+
+
 ## How to Install Without Docker
 
 While we strongly recommend using our convenient Docker container installation for optimal support, we understand that some situations may require a non-Docker setup, especially for development purposes. Please note that non-Docker installations are not officially supported, and you might need to troubleshoot on your own.