See general instructions here: http://www.mielkesfarm.com/felt_soap.htm)
One thing that can be helpful when felting soap -- wrap the soap in wool, and stuff the whole thing into a pantyhose leg. It holds the wool on when you are starting out the felting process. Be sure to pull the pantyhose off the felting soap/wool before it gets felted onto it, itself.
And if you have a pantyhose free zone at home, the local goodwill/salvation army probably has buckets of them.
Oh -- and if you don't have a washing board or felting board -- take your colander, turn it upside down, and use the underside of it. That helps, too!
(posted by me on spindlers, this day)