What is involved in changing the fuel injector's spider valve on a 1993 Blazer 4.3 Vortec engine?

Purchase the "Nut Kit" from you local dealer, purge the fuel, remove the two halves of the plenum, remove all the old parts, gaskets from both sections if they have stuck to it and put everything back. Now this of course is the simple version without much detail, but the basics. Best if you purchase a shop manual if you pursue further repairs on your vehicle. The obvious when removing the necessary components from the area that you are attending to should be documented and note of which way the parts are and the way they go back. You can now a days with modern technology take digital pictures of the parts and return to look at their placement on your computer if need be and if you have one, which can make a mechanics life a little easier, especially if you need to stop for some reason and return later and pick up where you have left off. This job is not that difficult, a little time and patiences you can complete this. Parts will cost some dollars though.....