I think you could do this through a package using cliclean. Point this package to the collection of computers you want uninstalled. However, if they run SMSls.bat in logon script, they would re-install.
or, I all these clients are located on a particular subnet, you can modify your site boundaries to exclude this subnet. Once the client see that they do not belong to the site, (I think) they will automatically uninstall themselves.
Please post your results....I would be interested in finging out how you make out.
Later... Joseph L. Poandl
MCSE 2000