open your simpleviewerconfig.xml in an editor
find this part:

adminUsername="admin" adminPassword="oaisufofbo36(this could be anything)42no7t"

and replace with:

adminUsername="admin" adminPassword="21232f297a57a5a743894a0e4a801fc3"

now your login is reset:
admin
and your pass is reset:
admin

goodluck

martin