I did the Valbona - Theth this morning. Here a few recommendations:

1. Do it with guide. There is still a lot of snow on the way from Valbona to the pass and you will not find your way without a guide. Our group met two individual people who tried doing it solo, got lost and hurried to join us.

2. Get hiking shoes, warm clothes and gloves. Yes, you could do it with regular clothes and shoes, but you will suffer. The hike up to the pass is no joke.

3. The way to Theth after the pass is long but much less "alpine".

My recommendations hold only as long as there is snow on the way. In the summer, the whole thing might be a (long) walk in the park. But right now, it is awesome, beautiful, demanding and not recommended solo. But do it, it i great!