It'll need a new blower motor resistor pack to cure the variable speed.
Here's a video on how to do it on another make of car to give you some idea.
http://www.youtube.com/watch?v=EsKIRuK7his&feature=fvsr
As for the hot air only, either a cable has come adrift or a valve has got stuck. A complete flush of the cooling system, and renewal of your antifreeze mixture may help clearing any crud out.
ChicksFan, October 2011
