Here is the upgrade documentation for MARS for your reference:
http://www.cisco.com/en/US/docs/security/security_management/cs-mars/6.0/initial/configuration/upgrade.html
What is the version of MARS you are running, and what do you want to upgrade it to? Please also be advised that it's incremental upgrade for MARS, ie: if you are running 6.0.1, and would like to upgrade to 6.0.5, upgrade path would be 6.0.1 --> 6.0.2 --> 6.0.3 --> 6.0.4 --> 6.0.5