Lay your pattern over the piece of fabric you’ve choosen to use as a patch.
It is important to choose a fabric that is only slightly heavier than your sweater, such as corduroy or a felted sweater. Anything heavier, such as denim or leather, may cause the sweater to tear.
To felt a sweater, simply put a 100% wool sweater through the washer and dryer. When it comes out, the sweater should be shrunken and have a very tight weave.
Pin your pattern piece onto your patch fabric.
If you double up the patch fabric before you pin you will get two identical patches, one for each side.
Slide the sleeve over the arm of your sewing machine, just like you’d put the sleeve over your own arm.
You may need to remove the table from your sewing machine to allow the sweater sleeve to slide over the sewing machine arm. Check you sewing machine manual for specific instructions on your machine.