(in your case /hotrod)
then just just zmprov mcf +zimbraInstalledSkin hotrod
to remove it's zmprov mcf -zimbraInstalledSkin <skintoremove>
To get a list of the currently installed skins:
zmprov gcf zimbraInstalledSkin
zmprov mcf zimbraInstalledSkin <skin1> zimbraInstalledSkin <skin2> etc...
but for this method you'd need to list ALL the skins you want to include, the ones you don't want should be left off the list. (if you fail to list even the currently installed ones it actually uninstalls them)
you may neeed a tomcat stop/start after the zmprov mcf sometimes