l have a 1995 gmc jimmy and l have a plugged fuel injector can l change just the onefuel injector or do l have to change the hole kit also can someone with knowledge of gmc not a mechanic change this or should l bring it to the garage

If its the 4.3 you have to change them as a collective group.

I've done them, they are not cheap.
You do need special tools, but they rent them at any Checker, Krugers, or autozone.

did you try injector cleaner first as gm recommends not the junk they sell over the counter thou but if you want to just replace injectors if you go that far id replace the spider lines also so you dont have to do it again but almost anyone can replace injectors these have to be replaced all you will need a book like a chiltons and a few special tools that they rent at auto parts store