Create informix user with root privilige: How?

Currently, I'm asked to re-install the INFORMIX-Online Version 5.01 on the other 486 pc running SCO UNIX System V/386 Release 3.2 Version 4.2. The Informix Installation Guide said that : 1. create a new group called "informix" and its group number should be greater than or equal to 100 2. create a new user called "informix" and its user ID number should be greater than or equal to 100 3. the user "informix" is the database equivalent of the UNIX "root" account The problems are : 1. The newly created group number and the user ID are both equal to 201 (The previous group and user ID numbers are 121). Should I need to change them from 201 back to 121? If so, then how to do it? 2. What does it mean the user "informix" is the database equivalent of the SCO UNIX r3.2 v4.2 "root" account? And how to make this? Pardon me for my ignorance and hope someone could shed some light to me. Many thanks.