Build simple SQL Query

I need some help builing an UPDATE sentence which changes some contents of the rows, based on another row. I want to set Property2 to 1800 from 2 rows which are similar to ID 2 (Sam), being similar means having same Property1. In this case I would change it for ID2 (Sam) and ID4(Jay), since ID1 already is 1800, ID3 have different property, and ID5 could be changed, however I already changed 2 rows. ID....Name....Property1....Property2.... 1.....Bob........0...........1800....... 2.....Sam........0.............0........ 3.....Ted........2.............0........ 4.....Jay........0.............0........ 5.....Eli........0.............0........ The result desired is this one: ID....Name....Property1....Property2.... 1.....Bob........0...........1800....... 2.....Sam........0...........1800....... 3.....Ted........2.............0........ 4.....Jay........0...........1800....... 5.....Eli........0.............0........ I was thinking something like this: UPDATE table SET Property2=1800 WHERE (Something) LIMIT 2. Could you please help me building this query? I need it right now.