Whistle from heater blower

Is it real hard to remove the heater blower from the 98 K1500? In the Haynes manual they talk about chopping off a piece of plastic and remounting using a press of some sort?! Sounds messy. The fan is driving me nuts because it whistles at low speed. Thanks!

Its not that hard to replace just get something comfortable to put your knees on cause your head will spoend alot of time ont the floor board! the manual should walk you through it.