add uninstall section

Author: stuffo

README.md

@@ -22,8 +22,14 @@ Install
    ``apt install ./linux-image-4.10.3-041003-generic_4.10.3-041003.201703142331_amd64.deb ``
 3. Install this package:  
    ``apt install ./scaleway-ubuntukernel_1.0-1_amd64.deb ``
-4. Disable Ubuntu kexec service (required as it is incompatible with this)  
-   `` systemctl disable kexec && reboot ``
+4. Disable Ubuntu kexec service (required as Ubuntu will kexec to early for us and leave us with a dirty filesystem)  
+   `` systemctl disable kexec ``
+5. Reboot. That's it. Your system will kexec into your Ubuntu kernel on startup.
+   
+Uninstall
+=========
+Either remove the package or just disable the service:
+``systemctl disable scaleway-ubuntukernel``
 
 Debugging
 =========