Waters Xevo TQD Operator's, Overview And Maintenance Manual page 187

11. Use the combined 2.5-mm Allen wrench and cone extraction tool to
unscrew the 4 mounting-flange screws.
Take care not to drop the screws inside the lower cover.
Tip:
Lamp mounting flange
Mounting-flange screw
TP03205
APPI/APCI source—replacing the APPI lamp drive seals 4-111