Paul the Mussalla path goes from the top of the mountain right back down to the Rila and is superb if conditions are right, it takes about 30 minutes but if no new snow i think you will find it is shut. Good luck for fresh snow
when you look at the map it doesnt seem clear how to get on the mussala pathway but in practice it is quite easy long and twisty and very pretty in places watch out for rocks and ice though
To get to the top of the Musala, take the gondola to the top and then ski down to the lowest drag lift. take this up and get as far over as you can towards the mountain. The Musala starts at the bottom of this run and goes along the valley past the two drags and down the mountain. Only its closed so you won't be able to go further than a few hundred metres.