The process is the same as the first time you installed the software except that you'll be doing it from the 2nd computer:
You will probably want to transfer the patterns from your old computer to your new one. Step-by-step instructions for that are here.
NOTE: Although the license agreement states that you may install the software on up to 2 computers, sharing your license violates the software's License Agreement. Each person who uses the software should pay for their own license.