Takes me about 6-7 hours to do them , and another 30 minutes or so to do the valve adjustment while your in there. It isn't a bad job, but there are soem things to be careful of. I ALWAYS go in with a pair of large pliers and rotate the injectors side to side after I loosen the hold down bolt to help break the o-ring seal to help prevent the cups from pulling. Also there is a feel to pulling them as to help avoid pulling the cups. If the cups do pull out you need to clean them up and reseal them properly or else you will start puking coolant out i nshort order. It isn't a bad job, but you will need a few tools that some may not have. A 5MM ball end allen socket(A GOOD one, not a cheapy) helps alot in getting the drivers side valve cover off. The rear bolts are TIGHT to say the least against the firewall. And I believe it is a 8MM allen socket to do the inejctor hold down bolts. Also it's the perfect time to do the t-stats(OEM or AC DECLO ONLY), and the turbo coolant hose going to the turbo(3/8" PUROSIL silicone hose is preferred).
