Yes, those are the items and you need a tech for replace them.
Would this be the correct item?
Is this something that is easily replaced by myself or will it require an official technician?
I think you need to replace the magenta developr housing and the magenta developer material.
My Phaser 7500 keeps emptying all my magenta toner into the waste cartridge. I can hardly print anything as it keeps doing this. Any suggestions? I tried swithcing two of imaging units to see if that was the issue (swapping magenta imaging unit with yellow imaging unit). But the magenta one was still emptied, not the yellow one.