Overriding the url REST web service consumer
Put variable name value "restUrl" manually in PutContextVar activity
Overriding the set values for the named parameters
You can override the values of parameters(query and header) by giving the value like "$$contextVarName$$" in REST Consumer GUI and create a contextVar with same variable name which is given in GUI surrounded by $$ (like "contextVarName" use as varible name), the value which is given corresponding to contextVar will be overridden dynamically.
Overriding the names and values for the named parameters
If you want to override parameter`s name and value both, then you can override it by putting variable name "resourceParameterXML" manually and in value field you have to provide the XML of parametes(format of XML is given below) in PutContextVar.
Format of XML: