Download TinyRF-v1.7.zip from below and extract it in your Arduino libraries folder. Restart Arduino IDE.
For your convenience another library called TinyRF_85-v1.7.zip is also provided. It has the buffer size reduced to compensate for the low RAM of the ATtiny85.
You can install it alongside the normal TinyRF library and include it whenever you want to use an ATtiny85 or similar microcontroller as receiver. This way you don't have to keep changing the buffer size in Settings.h every time you want to use a low memory MCU.
Feel free to open an issue if you encountered any problem or had any questions.