How to remove !

[Gordy1956]

Heater,blower resistor gave up,so time to change,But, removed 4 screws on black box that resistor goes into,removed 2 screws holding resistor in but not enough room to pull it out, black box is loose but can't remove it,have I missed somthing,don't want to force the black box in case I break somthing picture included if any use,any ideas welcome, ThanksView attachment 311462