I figured out how to change the knob out 2 nights ago. I used 2 flathead screwdrivers. One needs to be really small to take off the 2 screws that hold the silver shimano decal on the knob. After removing the 2 screws and silver plate, put it aside as they are very small screws (i.e. hard to find once you lose them!). After that, you'll see one more threaded bushing you need to unscrew by using a slightly larger screwdriver. After you remove this gold threaded bushing, you can remove the knob and put the other power T knob on the handle.
This is how I removed the knob off my Saragosa 18000....hope it's the same for your Stella 10k.
TLs
Brian