How to fix E1 error on HP LaserJet PRO M1132 not picking up paper

This is how to fix E1 error on a HP LaserJet PRO M1132 MFP. The printer is full of lose toner, the pick-up roller is very dirty and it can't pick up the paper. You have to cover the gap that leads to the laser unit, so that the fine toner won't enter and stick to the mirrors of the laser unit when you blow compressed air to clean. If toner sticks on the laser unit mirrors it will result in fade prints, and you'll have to take out the laser unit and clean it. The procedure is almost the same for the following printers: HP Laserjet M1120 MFP, HP Laserjet M1132 MFP, HP Laserjet M1136 MFP, HP Laserjet M1210 MFP SERIES, HP Laserjet M1212 NF, HP Laserjet M1217 NFW, HP Laserjet M1522 N MFP, HP Laserjet P1002, HP Laserjet P1005, HP Laserjet P1006, HP Laserjet P1007, HP Laserjet P1008, HP LaserJet P1009, HP Laserjet P1100, HP Laserjet P1101, HP Laserjet P1102, HP Laserjet P1103, HP Laserjet P1104, HP Laserjet P1106, HP Laserjet P1504, HP Laserjet P1505