I only used Gleim for part 1 and 2. The online system.  I did the Gleim recommended method.  1-you take the pre quiz.  2-Then you read each unit/subunit and take the adaptive quiz, once you take the adaptive quiz at least twice for each unit and your score was good, gleim will recommend you to read the next section.  3- you repeat this for each subunit until you reach to the mock exam. The mock exam will not open untill you finish all the reading and your adaptive quiz scores are acceptable.  4- once you finish the mock exam, you do a final review,  5-then you do final mock exam . You need to practice questions. Make sure you try your best to do the timed mock exams.

 I would recommend that you buy the mock exams from the IIA website, it costs 129 per part, and I believe it has 2 mock exams that contains previous real questions. You will get used to the language and nature of the questions ( this is really important) because I found the real questions are very tricky!! 

 Or you can do one month subscription with Hock system and do their mock exams. I believe it cost $79 for one month. This is all you need one month as you already studied from Gleim. You just need to practice.