Hi
With regards to your first question about business packages, please have a look here:
https://help.sap.com/erp_hcm_ias_2012_03/helpdata/en/42/ee6fc537663ee3e10000000a1553f6/frameset.htm
In the link above you will see an entry for the MIM role, and if you click on that you will see the techincal details for this package, as per your second question.
Once you have installed this BP, and the role is assigned to user(s), then upon launching the portal, you will find the entry point into MIM.
Good luck, and if you run into issues, reach out to your portal consultant who will be well versed in BPs and their installation.
Regards,
Ion Barbu