You'll have to enable an SNMP read/write community on the router, then enable system-shutdown with "snmp-server system-shutdown". This will enable you to do a remote reload of the router with SNMP.
The MIB OID for the reload-command is .1.3.6.1.4.1.9.2.9.9.0
You should send an integer value of 2.
This is all described in this link:
http://www.cisco.com/warp/customer/477/SNMP/snmp_faq.html#17
//Stig
