From Sofia airport
take bus number 84 and get off on the station named "Orlov most". In cyrilic we write: "Орлов мост" - means "Eagle bridge". Go under the underpass of the street and keep walking along the river in the street named "Evlogi Georgiev". On the second bridge you cross the river and you are on the right street "Nikolay Gogol". Walk about 50 meters more on the left side and you are in front of the Guesthouse.
If you land on Terminal 2, you could use also the metro(subway). The line goes directly from Sofia University to Terminal 2. Please, have in mind that the distance between Terminal 1 and 2 is big and I would not recommend to walk it!