Replacing Hornby worm

I don't know the loco in question, but this works for most motors/shafts:

Cut a solt in a piece of metal so that the motor shaft can be slid into the slot; motor below the metal, worm above. Grip/support the metal over a vice (or similar) such that the motor is **not** gripped. Use a hammer (and optionally a punch) to tap the motor shaft downwards, causing the worm to slide up the shaft. Be ready to catch the motor if/when it slides free.

The method means that the chances of bending the motor shaft, or buggering the motor bearings are much reduced.

Alternatively, as its plastic and if you plan to throw the worm away, then a hot soldering iron will melt the worm quickly so it can be removed.

- Nigel

In line with Nigel's idea of melting the worm ...

Grip the drive shaft between the motor and the worm with a pair of pointed nose pliers to also act as heat sink.

Get a low wattage soldering iron with a fine tip and place on worm end of shaft and hold until worm loosens and slide off.

Try to clean off all the glue from the shaft prior to it cooling.

"Gerald H" wrote

Just pull.

John.