You need to be able to remember those and read them back correctly.
I had to read back airways clearances for years. I relied totally on hearing the words in my mind's ear. There was NO visual image of the clearance. The thing is, for half a lifetime I wasn't really aware there was much wrong, I just got on with it.
I would be worried about the numerical side however, one would have to put something on paper - or the mental equivalent of a scratchpad - after the verbal part was over. Only periods of simulation would be of help in assessing this. Even MS Flt Sim can be of help in this area. A good and patient friend would also be useful.
If you can't screw in the numbers, on for example an altimeter, then you are going to have to see if this can be improved. The above mentioned thing about hard wiring is very true, but tricks can be learned to overcome a specific blindness.
Whatever method is used, it would have to be reliable. You would have to
know whatever was put in the altimeter setting was the pressure you'd been given. Again, only practice and testing will reveal this, and this should all be out of the way before you start paying for the real aircraft.