The easy way is to hold down the ink button for 5 seconds and let it do a head cleaning. Repeat this a couple times until you see magenta in the capping station. While you are doing this...hold the cyan and magenta bottles only, above the machine to create more head pressure. Lower the bottles back to the normal position before you print or nozzle check.
Then do another nozzle check to see if your cyan and magenta improve. If it does not...clip the black, yellow and white lines shut. Then hook your syringe up the the waste line and draw your syringe to pull ink through the magenta and cyan lines. (make sure your head is parked in its home position before you do this) If you don't have clips on your lines...then pinch them shut with forceps or binder clips. Try drawing with the syringe for a good 10 seconds. Unclip all the lines...do another head cleaning with the ink button...then run another nozzle check. If that does not work...the next step is pulling out the head and flushing it. I have a video if you need it.