Q.What do I do when my Chinese Evergreen gets leggy?
I have a Chinese Evergreen that I got 10 years ago. The original part of the plant has gotten leggy and the only way I can keep it from falling over is to stake it. A new plant has emerged in the same pot and it’s doing well. Is there anything I can do besides stake up the old plant? The top of it is doing well and putting out new leaves. Thanks.

You can trim your Chinese Evergreen and actually propagate from those cuttings if you would like.
You could do this with the larger leggy portion of the plant, then separate the smaller plant into a new pot.
https://www.gardeningknowhow.com/houseplants/chinese-evergreen/chinese-evergreen-plants.htm