From Silom, I would get on the expressway at Suriwong (paying 40 baht toll), then follow the signs for "Rama IX". Go past the Rama IX and Ramkhamhaeng exits (paying an extra 25 baht toll) and get off at the "Srinakarin Road" exit. That will put you on Rama IX Road not far from Soi 49 and going the right direction. Just keep going straight for a couple hundred meters and you'll see it on your left. Once in Rama IX Soi 49, you'll see Falcon just inside the first sub-soi on your right. Parking is where you can find it along the street (not difficult).