saving a heather
I bought two heathers. Unfortunately, I only got one of them in the ground right away (it's doing fine). The other one has turned brown and looks dead with maybe a tiny bit of green deep in the middle.
Let's start with an article on growing heather: https://www.gardeningknowhow.com/ornamental/flowers/heather/growing-heather.htm
For the dead one, gently cut away as much of the dead part as possible. Pull it out of the pot, spread the roots gently away from the soil, and cut away dead roots that you see, also. Then go ahead and plant it. It may not live, but then again it may. With plants it's often "nothing ventured, nothing gained."