You will need:
1. Break pad
3. Allen or socket wrench
Step 1: Ensure that your current break pad is okay to use-- it is not to worn and it is the correct break pad for the particular bike that you are working with.
Step 2: Wrap the rear 1/4 of your break pad with an elastic (see image)
Step 3: Set break pad in designated break arm
Step 4: Press break pad against rim ensuring that the pad is aligned flush to the rim.
Step 5: Tighten break pad in place and remove elastic.
If the installation is done correctly your break pads will be properly toed in (see image)