Brilliant video, agreed. (The first 9 minutes are really great, then he gets distracted and starts rambling.)
He answers your question right there in the video. He says, reifications are overcome by questioning them.
Let me explain in my own words.
Reifications is the substance the ego is made from. Since ego is a conglomerate of reifications, by overcoming the ego you overcome reifications and vice versa.
And how do you overcome the ego? By letting go of attachments, biases, prejudices, overgeneralizations.
How? Start by watching yourself in the middle of daily situations, watching your behavior and your mind, your state of mind, your emotions. See how you react, how you get angry or irritated or scared etc. See what situations and most importantly what thoughts trigger these reactions these states in you.
Then try and notice how in these situations the ego is trying to defend itself. The conglomerate of reifications is trying to defend itself by convincing itself that its reifications are right. It's a kind of feeding, upadana, the ego is feeding itself by cycling over these thoughts, by holding onto these reifications, prejudices, overgeneralizations and so on.
The more you watch it the better you see it, and then you should make a resolve to not allow the ego to keep on feeding and defending itself. You make a promise to yourself that every time you see your ego justify itself, you will challenge it.
For example, if you have a prejudice against dark-skinned people, you catch your ego holding on to it. You catch yourself feeding onto the thought "I'm better because my skin is lighter. I am more civilized." You notice how your ego tries to convince itself that it is better than someone else. As soon as you notice that, you stop it. You tell your ego: "not so fast, this is a reification. There are plenty of horrible people with white skin and plenty of highly evolved people with dark skin". Then you force yourself to behave in accordance with this understanding. You go and talk with dark-skinned people with friendly love and friendly respect. Most importantly, you change your attitude.
Similarly in other situations, whenever you feel "it must be this way only and not another", "only this is good - the rest is bad", "only my opinion is valid, the other is not". All of these are reifications the ego feeds on. By systematically stalking and catching the ego in the middle of real life situations, social situations, especially the ones where you get emotional - you can recognize and overcome your reifications.
Once you develop the habit of doing this, your mind will automatically challenge its stereotypes and generalizations.
The most important point to understand, you don't need to be in a monastery in order to practice prajnaparamita. You must practice right in the middle of Samsara, because reifications are the very building blocks of Samsara itself. By working with reifications as they manifest in your emotional reactions in your everyday life you're not just learning to see things as they are - you are walking the real path to real Enlightenment.
By the way, when the speaker in that video says that animals do not reify nor suffer, with all respect he is not well-informed on this detail. Animals do engage in semiosis and as all semiosis is essentially reification therefore animals do reify. For example when a bear smells honey and assumes that means food (an example of primitive semiosis), if he or she climbs a tree and finds an empty hive the bear's assumptions fail and there's arising of dukkha, of course! It's just not as deep and convoluted a tangle as it is with humans but animals absolutely do reify and suffer.