new to myturbodiesel.com & forum, problem with immobilizer on 2002 tdi

Hello, Great web site. I'am new to forums/posting. I was looking for some detailed instructions on how to program the immobilizer part of the key with vag-com I have the original key [which works fine] but the second key and the valet key [which are both original as well] do not work. They start the engine then it stops after about 2 seconds with immobilizer light displaying. I have the SKC, but without some detailed instructions I'am a bit hesitant to try. Thanks in advance.