Im having the EXACT problem. i was told it could be the Slave thats making it so difficult to shift. no idea what the rattling is.
It CAN be a do it yourselfer. but its somewhat difficult. not hard. just difficult.
Slaves and masters are around 60 each. and clutches (With throwout bearing pressureplate and friction plate) are anywhere between 90 - 400$ <-- Includes slave cyclinder and master cylinder.
But if someone could explain what the hell that rattling is. i would be VERY thankfull.
Heres a link to my Thread just liek this if you need any info from IT as well. My Thread.