You can install packages... Try reading the first post...
No offense dude but I'm REALLY getting tired of you and everyone else asking this. What FW is this? 3.55. Do we have the 3.6x+ keys in 3.55? No. We have them in 3.6x+ FW. CEX or DEX makes no difference they came out at the same time how on earth is a FW released well before 3.6x suppose to know it's future keys!?!?! I do not understand what is so hard to grasp. No you can't play updated retail eboots that still require THE KEYS. MultiMAN should work as if you were on 3.55 CEX though so have at it >.>