Adding a GUI how-to for changing the external network

network/README.md

+### Existing Floating IP release
+
+First you need to release existing Floating IPs from your instances - go to **Project > Compute >  Instances**. Click on the menu **Actions** on the instance you whish to change and **Disassociate Floating IP** and specify that you wish to **Release Floating IP** WARN: After this action your project will no longer be able to use the floating IP address you released. Confirm that you wish to disassociate the floating IP by clicking on the **Disassociate** button. When you are done with all instances connected to your router you may continue with the next step.
+![](/network/images/instance1.png)
+
+### Clear Gateway
+
+Now, you should navigate yourself to the **Project > Network > Routers**. Click on the action **Clear Gateway** of your router. This action will disassociate the external network from your router, so your machines will not longer be able to access Internet. If you get an error go back to step 1 and **Disassociate your Floating IPs**.
+![](/network/images/clear-router1.png)
+
+### Set Gateway
+
+1. Now, you can set your gateway by clicking **Set Gateway**.
+![](/network/images/set-router1.png)
+
+2. Choose network you desire to use (e.g. **public-cesnet-78-128-251**) and confirm.
+![](/network/images/set-router2.png)
+
+### Allocate new Floating IP(s)
+
+1. Go to **Project > Network > Floating IPs** and click on the **Allocate IP to Project** button. Select **Pool** with the same value as the network you chose in the previous step and confirm it by clicking **Allocate IP**
+![](/network/images/allocate-fip.png)
+
+2. Now click on the **Associate** button next to the Floating IP you just created. Select **Port to be associated** with desired instance. Confirm with the **Associate** button. Repeat this section for all your machines requiring a Floating IP.
+![](/network/images/associate-fip.png)
+