In case you did not see this : ( credit to original poster ) :
Segun,
I have not received any official answer, but I found out how to uninstall 3.0 anyway.
The problem was that somehow the registry files pointed to an installation of 3.1 - probably as the result of a botched installation attempt of system update. These registry records made it impossible to remove 3.0 via the control panel uninstall routine - the registry information (3.1) was in conflict with the *.msi installer file (3.0).
The solution was using "windows installer cleanup", a free utility provided by Microsoft, to get rid of the (wrong) installer information. You will find the utitilty on the windows website.
Step 1: Check the current version of rnr (run rnr and check the version in the help file) - in my case it was 3.0
Step 2: Use "Windows installer cleanup", look for "rescue and recovery" and press remove
Step 3. Reinstall rnr x.y (3.0 in my case) by going to c:\ibmtools\apps\rnr and running tvtnr3.exe or whichever trtnrxy.exe
Step 4: Uninstall rnr x.y via the control panel uninstall routine.