Injectors are a DIY and fairly easy.
Removing the fuel rail will bring the injectors with it. Do a search on the various forums for that until you can get your hands on a Bentley Manual. I recommend www.e30tech.com
for the more advanced level of tech help, even though they aren't as friendly as bimmerwerkz. Here is a good idea of how to clean the injectors... Once you have removed the fuel rail and injectors, pull the injectors from the rail, and soak them in a bath of Mineral Spirits. It is a solvent and has similar properties to gasoline so it goes the same places that gas would go. Soak them for a couple hours, then pull them out, scrape any gunk off of them (usually with your fingernail is good enough) and then blow the injector out with a fine pointed air compressor hose. Make sure to blow them out in the same direction as the fuel flows! From fuel rail side through to injector side. Then make sure you have new Injector O-rings, lube them up with a little gas/mineral spirits/light oil to ensure a long life, reasseble the injectors into the rail, and pop the whole assembly back into the block. Then crank it up, (this will take longer than usual, as the fuel rail need to refill and get back up to pressure) and run the engine at idle for a few seconds, then kill it, take a look around the area for fuel leaks and such, then start it back up, let it idle for a few minutes while keeping an eye on the area, and sniffing around for leaks... if no problems, take it out for a gentle drive, come back, check them, and work your way up to full power leg straining power shifts!
I am overly cautious when it comes to working with fuel, but then again, I have never had a car burst into flames, so I must be doing SOMETHING right!
Hope this helps!