What's the proper procedure for getting rid of used up LiFe batteries such as those used in receiver packs?

The radio shack and batteries plus+ dispose of (send to recycle?) old batteries here. May try calling your local store and see if they do as well.

Same procedure as LiPo disposal, discharge it to 0 volts then you can toss it. There are many ways to do so, salt water, resistor, light bulb...

I thought LiFe would be different than the Lipos. Thanks.

Best Buy has bins for electronics and what not.

As does Home Depots. just make sure to drain it completely, then drop it in the bucket at Home Depot.

Nicer than me, I just dump my stuff in the bin and walk away.