as it's already loose you may be able to remove it
without taking the whole thing apart.
The orange bit has clips on it that hold it in place.
As it seems like they have broken off, you should be able to lift it out.
There is a power cable connected underneath it.
Disconnect the old one and push re-fit the new one.
If you cannot do this it means removing the downtubes and unscrewing the whole bottom assembly to remove it.
Not that difficult..........just time consuming!
Hope this helps.