The only specialist tools I used were a torque wrench, my grey matter, and years of experience working all over Africa. They dont have access to all new parts and keep their motors running for many hundreds of thousands of miles with whatever they've got to hand. New parts are OK if you've got the cash but with care many are perfectly reusable time and time again. Always replace worn parts, Nyloc nuts, and critical stuff such as head bolts etc. Also high torque items are designed to stretch on installation so often reuseing them is not a good idea if you have the choice as they will eventually snap. Of course all of the above is at your own risk but it works for me.
Once you remove the injector clamps the only thing keeping them in place is the O ring seal. I used a small pry bar to carefully lift the injectors from their seats. Dont lever on the solenoid part of the injector. You can also disconnect the loom from the ALL of injectors and crank the engine with the clamps loosened which can unseat any stubborn ones using the engine compression.
I used a thin bladed paint scraper to ease the copper washers from the injectors and a small electricians screwdriver to hook the O rings off. I then used some wire wool soaked in parafin to careffully clean the tips of the injectors as they had a slight build up of carbon. New O rings and washers slide on with finger pressure. You may have to use a smear of copper grease to hold the new copper washers in place as you insert the injector into its seat. Clean the injector seats in the head and make sure the injectors go back in the same cylinder position as they came out as they are coded to the ECU.
I re used the injector adjusters and lock nuts as they were not worn in any way.
I cleaned the rocker bolts and holes and reused them at the correct torque with a touch of non setting thread lock compound. I also reused the injector clamp bolts.
Hardest bit was getting the new rocker cover gasket to seal but once again I used a small wallpaper roller to give the thinnest of coats of some domestic silicone sealant and Bobs your mothers brother. Dont be tempted to over tighten the cover bolts as they are only torqued to something like 7 ft/lb from memory.
Like all things you have not done before it sounds complicated but once you get into it you'll wonder what all the fuss was about. It aint rocket science. Take your time, think through what you are doing, make sure the injector adjustments are done to the book, and you'll be fine.
One last thing. DONT be tempted to fire the engine with the rocker cover off to try and look for any leaks around the injectors. You will pump all of your engine oil all over your engine bay and the garage floor in about 10 seconds. I know because thats what happened to me. Took me two days to clean things up and I'm still finding oily bits - normally with my favourite shirt or jeans.