I like that Idea tankbear, much easier to buy the pinions and put them on knowing that a simple grub screw will hold it, then try and prize the pinion off and buckle the shaft of the motor. I've heard that the pinions are press fit and that you need a gear puller to remove them.
My gear system was from Welshdragon an Asiatam improved metal gearbox if I remember correctly and I didn't notice any removable screws on the pinion at all

I do have a set of old motors which I could practise on removing with the heat technique.
To be fair.. I need more power put on the floor at low speed, because my tank has got a bit fat

and I'll be damned if I'm sending him to slimming world or fat club as my sister fondly calls it.
What method would be the best to heat the pinion and spindle? Soldering iron? gas burner(cooker)? electric hob? or blow torch (I don't have one

)
-x se7en x-
@Tankbear in that ebay link, how many teeth should I get?

10, 12 or 14
nm I used a bit of grey matter and counted the pins on my motor I went for 10
