No, MG is garbage. Change the soil as soon as you can.
Regarding how to transplant, this is how I do it
If you have a pliable pot, wait until the soil is dry and push the opposing edges together. Do this all the way around. Hold the plant with the stem between your index and ring finger with your palm to the soil. Tip the plant sideways with your other hand holding the pot just enough so the rootball and soil slides into your hand (do not pull with the hand on the stem). Use your other hand to pull the pot away from the soil. Set the plant down in a garbage bag and very very gently go around the plant caressing it. Loosen the soil gently and some clumps should fall off leaving you with mostly a nice rootball and less bad MG soil. You wont remove all the soil, just remove whatever falls off with gentle touching. I recommend gloves for when you touch the roots. The next step is to have one hand under the plant supporting the roots and the other holding it by the stem, gently ease it into the new already prepared pot (enough soil for the plant to sit 2" inside the pot, valley in center for roots to fall into, then add topsoil until just under the top of the pot, when watered it will lower).
Its important to be careful how you orient the plant, you want it to be straight and not waste energy straightening itself out. Ensure that you push the plant in the pot far enough; you dont want the root level equal with the top of the pot. Its pretty simple - just dont be aggressive with it, know its a living thing, but also know its not gonna die if you accidently have one root break.
