They are not too bad, but you need the proper puller. Billetflow makes an awsome one, some others on the market are cheap crap and a waste of your money.
Link above also has the instuctions to give you an idea of what is involved. I did mine by myself, but its really helpful to have another person to help.
WWW.RPMOUTLET.COM ALSO OFFERS A GOOD PULLEY AND HAS EXCELLENT ON-LINE INSTRUCTIONS. ONCE THE PULLEY POPS IT THE COMES OFF PRETTY EASY. IT DOES TAKE TWO PEOPLE. REMEMBER TO USE AN ANTI-SIEZE LUBRICANT ON THE THREADS.