Done!
Now it looks happier.
Trimmed all the dead leaves and dead flowers spikes.
I haven't found any rotten roots, all were white and rigid.
There was a dying pbulb burried in the media but it as been always there. Since the plant seems to be happy I didn't removed it. Hopefully it will become a source for nutrients, like in nature.
As media I've used 2/3 medium size bark mixed with 1/3 of a mix suitable for epiphytes containing bark, perlite, leca and coconut husks.
This was still in the original pot when I bought it and the media was bark with traces of moss.
Some pics: