Typically, most of the configuration cannot be changed during runtime, as the Configuration object is immutable (and many components cache it). If you want to combine XML and programmatic configuration, just look into the code you use for loading XML configuration - you'll find ConfigurationBuilder, which can be modified. I won't give you concrete examples with such outdated versions.
Some attributes can be changed by management operation (JMX), but eviction settings are not among them. If you need to change this, you need to start a new cache and move the data manually between them.