Dell C3760dn Color Laser Printer - Manual (Page 321)

Maintaining Your Printer 319
5 Slightly pressing down the tab on the drum cartridge that you want to replace, pull it out halfway with one hand.
6 Support the drum cartridge with the other hand from underneath, and then pull it out completely.
7 Repeat the steps 5 and 6 to remove the other three cartridges.
Installing a Drum Cartridge
1 Unpack a new drum cartridge of the desired color.
2 Remove the orange protective cover from the drum cartridge.
3 Insert the drum cartridge into the associated cartridge slot, and then push until it stops.
4 Repeat the steps 1 to 3 to insert the other three cartridges.