have got some yellow 440 sti injectors to fit to my my95 wrx wagon, but how do i go about fitting them?

 

It's not fun. I think the worst thing is if they have the 'shield' still fitted over them. Otherwise if you're confident messing with the fuel system, allow yourself a day and you'll have it done I reckon.

 

Once you have undone the 2 x 8mm screw bolts (not 100% sure of the size)
on each cap. Then you will have to wiggle/turn the injector & pull them out of the rail.

I had both my fuel rails already off (spare) & I struggled like hell to get the injectors out.

 

If you havn't got a fuel pressure gauge to check held pressure before stating, then remove the plugs.
Switch on ignition and get the pump to prime, then crank it over.
Make to there are no large quantities of fuel flying out the plug holes.

It's common for them not to seat correctley hence fuel pisses into the bores. If you then crank the engine with a bore full of fuel there is a chance you will bend a rod.