1 - 3 hours
There were some small parts that are not described in the instructions where they hard to figure out how to place them back. Not 100% reliable instructions and the cover I got from ifixit.com had no screw hole for the sim injector holder!!!
Ask the ifixit.com to redo the instructions with more detail, is hard just to say: follow the steps in reverse order, IS NOT EXACTLY LIKE THAT!!