I2C on attiny85 ?

I have used I2C on an attiny but tried recently and....failed !.....I downloaded the library's and put them in my arduino library's folder but will not work ...when I did get it to work years ago I think that was with arduino IDE 1.5X so I guess many things have changed ..I know i cant just download and install ...poof
it works ....mmmm not working that way any thoughts on how to get this to work? I have I2C LCD,S
well several diffrent I2C sensors I would like to use with the attiny85/45..84 any Ideas ?