Loading Plug-ins - ARCAD 5250 and iSphere

Although, I have been trying to load the 5250 Arcad plug-in and the iSphere tool that I read about lately.
No matter what I have tried - zip file or extracted jar files, with the installation manager or with the install new software selection under help on RDp.
I tried the -clean option that someone suggested in the archives but no difference.
I get the message either that it couldn't find the jar file (after I had browsed to add it).
Or the message that it can't connect to it when I was adding a repository in installation manager. Also tried run as administrator for installation manager.
There must be something I have set wrong somewhere but I can't figure out what.
Is there a plug-in for dummies installation instructions somewhere.
I would appreciate any ideas. Thanks

HTH,
TIA,
Thanks,
Whichever applies

Dave B

Sometimes I get the feeling the whole world is against me, but deep down I know that's not true. Some of the smaller countries are neutral. -- Robert Orben (comedy writer)