Arduino attiny85 ir led remote

HI

I have created a project with my Arduino Uno that reads the input from an IR remote and then switches on my LED for 3 seconds and switches it off again, I then went on to use this idea to open my bedroom door with a remote. It worked fine but I now want to make it permanent using an attiny85 chip so I dnt have to glue my arduino next to my door.
I am new to Arduino, literally 2 weeks so I was proud of myself for pulling this off.

I have recently bought an attiny85 chip and have no idea how to get my sketch to work from the attiny85 so I no longer need to use the Arduino Uno.
I don't think it is too difficult a project but because I am new to this I do not know how to go about it.
I have setup the attiny85 files in my arduino program and everything shows. The problem now is how to code it and upload the sketch to the chip

Please Help!!
I am totally clueless as to how to go about this.

(FWIW - This should have been posted in 'Microcontrollers')

Thanks for the response and the link. I will then repost it in microcontrollers