Is this a front-loading machine? The main drive motor on these is usually located below the drum and mounted so as to be part of the overall drum suspension system (i.e. fixed to the drum mounting so that it moves with it on its dampers and springs.
If you remove the rear panel, you should be able to access the motor underneath the drum, although some of the newer machines don't have a removable rear panel, in which case your best bet is to lay the machine on its side and go in from underneath.
Newer units often have multi-way connectors which are just a push/snap fit onto the motor terminals, but if there are multiple connectors and it's not obvious which is which or which way round they go, make a note before disconnecting them. Also, make a note of exactly where washers, spacers, and similar mounting hardware go as you unbolt the motor.
And I'm sure I don't have to remind you to unplug before starting, do I?
