A mini bus from Zhovkva to Lviv could be taken near Dominican church, bus will take you to Kulish street a few blocks behind Lviv Theater in Svobody avenue. It is written that it goes to Lviv. Trip takes about 30 minutes and costs really not so much, around 5 grivens.
The service by that time was provided by old mini buses, I think in Lithuania these are already in museums :)
By the way, it is possible to take a bus to Krehiv to (a monastery 12 kilometers away), but it is pity bus didn't come at all and I decided to come back directly to Lviv.
you can catch a mini-bus from Zhovkva to Krekhiv. a bus stop is located next to the St. Laurence Cathedral (little Wawel). in reality it sheduled to go every 40 min, in practice - it depends ;) so you can either wait for 14:10 bus that goes on time, of try to flag a car. please note that the last mini bus from Krekhiv to Lviv departs at 8 pm (earlier departure times - 16:10, 18:20)
a bus from Zhovkva to Krekhiv costs 1.5 UAH (S0.30), from Krekhiv to Lviv 4 UAH (S0.80). it will take you to the bus station #2 (225, Khmelnytsky St.), which is located out of the city center. there are several Lviv marshrutkas, which cruse from there to the city center.
you can get to Zhovkva by a mini-bus from several locations: one is just across the TsUM, leaves every 30 min.; another - just couple blocks further (Kulish St), leaves every 15 min. I chose the second one since it was less crowded.
a one-way ticket to Zhovkva costs 3 UAH (0.60 cents)
travel time is about 25-30 min depending on the number of stops it makes.
the mini-bus stops will bring you close to the Dominican Monastery and the Synagogue.