- fixed instructions

README.1st

@@ -26,8 +26,10 @@ To install, do the following:
 
 * copy SLUBStoragePlugin.jar to /operational_shared/plugins/custom/ on target
   system
-* copy SLUBStoragePlugin.jar to /operational_shared/plugins/custom/deploy on
-  target system
-* use dps user to restart Rosetta: "su dps; dps_restart"
+* log into Rosetta Administration -> Plug-In Management -> Custom
+    on new install: -> Add Plug-In Instance -> SLUBStoragePlugin -> Install
+    on upgrade: -> SLUBStoragePlugin -> More Actions -> Upgrade
+* use dps user to restart Rosetta: "sudo su dps; dps_restart" or alternatively
+  restart Rosetta systemd service: "sudo systemctl restart exlibris"
 
 If you have any questions, feel free to ask andreas.romeyke@slub-dresden.de