Hi Sam
As Vadim has mentioned, there are various options to consume these web services and this will depend on the platform and skillset available in your organization.
However, I think you are hoping to do this in ABAP, and yes, that is possible too. You just need to generate a consumer proxy based on the WSDL file of the ID API, and code the appropriate logic to execute the proxy. The following blog provides step by step guide for it.
Consuming WebServices directly from ABAP
As a bonus 
, I managed to find a program I did ages ago using 7.0's API that creates a full suite of objects for a complete configuration scenario. I'm attaching it here, hopefully it might be a useful reference for you. (Note that the program will not activate/compile in your system because it depends on the existence of all the proxy objects).
Rgds
Eng Swee