Do you have old sweaters laying around? Is the yarn simply gorgeous or do you just want to re-use it? Is the sweater to mishapen to wear or just plain ugly, but the yarn is excellent? Did make an absolutely marvelous sweater, only to try it on and discover you should burn the pattern? Well then, recycle that yarn!!!
There are two methods of recycling a sweater into re-usable yarn. The first method is done from a work-in-progress (wip), the second method is done from an already finished-object (fo).
Step 1: Remove the needles
Here, we will begin by removing the needles from the offending sweater. This is done by simply sliding the stitches off of the needles.
Then, lay the offending sweater flat sew you can begin frogging. Frogging is the process of ripping the stitches out: As in, "Rip it, rip it, rip it!"
Step 2: Frog It!!
Begin frogging by grasping the unknit yarn and carefully rip out all of the stitches of the sweater. You will have to undo all of the yarn ends that were woven in, before you come to them (I don't hide my ends until I'm satisfied with it when I try it on.). This can be done by using a blunt tapestry needle to fish out the woven in ends. Also undo any knots you come across.
As you rip out the stitches, gently wind the yarn into a ball.
Frequently remind yourself that you will not knit clothes that will not fit you like the model in the picture, unless the model in the picture has a similar form to your own.
Step 3: Continue frogging the sweater.
Keep pulling the yarn out and winding it into a ball as you go.
Wind gently so you do not stretch the yarn out anymore than it is already. This is especially important if you are unraveling a cotton, silk or wool sweater.