Its not the switch that is bad its the blower resistor that has gone (a
common problem on some GM cars).

If you are not mechanically inclined maybe you should leave it to a
mechanic. Or go to your local library and get the book on the Malibu, it
tells you how to change it out.

The speeds 1 to 3 on the fan motor do not work, just 4 and 5.

Where can I source an economical replacement switch?  How much?

2) Is it hard to change this switch?  How do you get to it?

LeFort

See http://www.malibu02.netfirms.com/resistwalk.htm
for directions on changing the resister card (about $25-$30 part).

After reading, you can decide if it's something you want to
tackle.

Regards,
John