I came across a solution to modify timer jobs from the Central Admin interface. This is the equivalent of using the stsadm -o setproperty command. The best part is you can modify your timer jobs without having to redeploy them!
When you install it, you will get a link in your Central Administration site to ‘Manage Timer Jobs’.
Wait! Theres more, you can also deploy your own custom timer jobs, update job properties and schedule all from this neat interface.
Read more and download here: http://sptimerjobadmin.codeplex.com