The best time to re-pot is in the Spring around March as you have said. Money plants thrive better when they are slightly pot bound so when you re-pot only go one size up, as they like a tight root system. Use Loam based potting compost and only water when the soil starts to dry out. Over watering can stop the roots from growing and in turn makes the plant top heavy. That sounds like a very large plant you have west ham fan so it will take three people to get it out of the pot. Two people will have to hold it up off the floor and the other will have to look underneath to see if the roots are coming through the holes in the bottom and then cut them off. Then gently tap the pot all the way around with a hand trowel or fork to loosen the plant.Hopefully it will come away,Good luck