on the right side remove the 2 screws remove the end cap remove the drum remove the charge roller remove the 2 screws below the transparent sealing blade
hp laserjet 100 color mfp m175nw image drum, take the wiper blade out be careful not to damage the recovery blade that is located next to the wiper blade if this blade is bent in any way, the cartridge will leak
the recovery blade prevent excess toner from falling out from the waste hopper damp all toner from the waste bin it's better to use compressed air if not, clean the cartridge as well as possible at open air do not breathe the toner dust inspect the seals of the wiper blade often the wiper blade is reusable clean the wiper blade with isopropyl alcohol
lubricate the working edge of the blade with toner clean the charge roller with a soft cloth and water the charge roller places the initial charge on the drum as well as erase the residual charge at the end of the print cycle reinstall the wiper blade in place install the charge roller lubricate the drum with toner or zync stearate or other lubricant or the wiper blade may damage it
install the drum install the end cap turn the drum by hand, to make sure it doesn't flip the blade verify there is no toner ring on the drum in this case the wiper blade is damaged the chip is a page counter and you have to replace it each cycle
cut both ends of rails securing the existing chip and replace with the new chip use a bit of glue to fix the chip in position
and the work is done
