I did this once, not likely to repeat, it was a very long bus ride. Sorry I don't wear a watch, so not sure how long exactly, maybe 45 minutes ...
The web site with the bus lines is www.siteur.gob.mx/sitren/lĂnea-1.html should show you the route for the line 1 siren bus. Also when you take the bus, you can not see the mall from the road or the bus stop, I had asked enough people where the stop was and they threw me off the bus at the correct stop. This bus goes from centro Guadalajara to the mall, I have no idea if there would be one from the bus station to the mall, As my spanish is lacking, I only take the buses that I can look up online.
Good luck with your trip, it will be an all day adventure, if you have any further questions about this, or anything else, holler back